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Sample records for apparent false negative

  1. DNA typing by microbead arrays and PCR-SSP: apparent false-negative or -positive hybridization or amplification signals disclose new HLA-B and -DRB1 alleles.

    PubMed

    Rahal, M; Kervaire, B; Villard, J; Tiercy, J-M

    2008-03-01

    Human leukocyte antigen (HLA) typing by polymerase chain reaction-sequence-specific oligonucleotide (PCR-SSO) hybridization on solid phase (microbead assay) or polymerase chain reaction-sequence-specific primers (PCR-SSP) requires interpretation softwares to detect all possible allele combinations. These programs propose allele calls by taking into account false-positive or false-negative signal(s). The laboratory has the option to validate typing results in the presence of strongly cross-reacting or apparent false-negative signals. Alternatively, these seemingly aberrant signals may disclose novel variants. We report here four new HLA-B (B*5620 and B*5716) and HLA-DRB1 alleles (DRB1*110107 and DRB1*1474) that were detected by apparent false-negative or -positive hybridization or amplification patterns, and ultimately resolved by sequencing. To avoid allele misassignments, a comprehensive evaluation of acquired data as documented in a quality assurance system is therefore required to confirm unambiguous typing interpretation.

  2. Accounting for false negatives in hotspot detection

    SciTech Connect

    Sego, Landon H.; Wilson, John E.

    2007-08-28

    Hotspot sampling designs are used in environmental sampling to identify the location of one (or more) contiguous regions of elevated contamination. These regions are known as hotspots. The problem of how to calculate the probability of detecting an elliptical hotspot using a rectangular or triangular grid of sampling points was addressed by Singer and Wickman in 1969. This approach presumed that any sample which coincided with a hotspot would detect the hotspot without error. However, for many sampling methodologies, there is a chance that the hotspot will not be detected even though it has been sampled directly--a false negative. We present a mathematical solution and a numerical algorithm which account for false negatives when calculating the probability of detecting hotspots that are circular in shape.

  3. Underpowered samples, false negatives, and unconscious learning.

    PubMed

    Vadillo, Miguel A; Konstantinidis, Emmanouil; Shanks, David R

    2016-02-01

    The scientific community has witnessed growing concern about the high rate of false positives and unreliable results within the psychological literature, but the harmful impact of false negatives has been largely ignored. False negatives are particularly concerning in research areas where demonstrating the absence of an effect is crucial, such as studies of unconscious or implicit processing. Research on implicit processes seeks evidence of above-chance performance on some implicit behavioral measure at the same time as chance-level performance (that is, a null result) on an explicit measure of awareness. A systematic review of 73 studies of contextual cuing, a popular implicit learning paradigm, involving 181 statistical analyses of awareness tests, reveals how underpowered studies can lead to failure to reject a false null hypothesis. Among the studies that reported sufficient information, the meta-analytic effect size across awareness tests was d z = 0.31 (95 % CI 0.24-0.37), showing that participants' learning in these experiments was conscious. The unusually large number of positive results in this literature cannot be explained by selective publication. Instead, our analyses demonstrate that these tests are typically insensitive and underpowered to detect medium to small, but true, effects in awareness tests. These findings challenge a widespread and theoretically important claim about the extent of unconscious human cognition.

  4. False negative clinical diagnoses of malignant melanoma.

    PubMed

    Osborne, J E; Bourke, J F; Graham-Brown, R A; Hutchinson, P E

    1999-05-01

    The false negative rate for the clinical diagnosis (FNR) for malignant melanoma is reported to be of the order of 20-50%. The aim of this study was to investigate possible predictor variables for FNR, with particular reference to the features and score of the seven-point check-list within the total population (778) of histologically proved malignant melanomas presenting in Leicestershire between 1982 and 1996. The FNR was 18.5%. The check-list would have failed as a referral indication in only 0.8-1. 1% of the lesions. The major check-list features occurred more commonly than the minor features, excepting size >/= 7 mm, confirming the diagnostic importance of the major criteria. The FNR was unaffected by age or sex. More rarely involved sites had higher rates (31-42%), and the face was a particularly difficult diagnostic site. Clinical features of lesions associated with a higher FNR were lack of irregular pigmentation and shape, altered sensation, the presence of inflammation and size < 7 mm. The FNR was inversely related to the total score and major feature score, but directly related to the minor score. The minor features, in addition to the major features, are potentially valuable in avoiding false negative diagnoses and we suggest their retention as part of the check-list. There was only one patient, in whom the diagnosis of melanoma was initially missed and who was not biopsied on presentation to hospital, who re-presented after 1 year. However, the study illustrates the importance of avoiding a false negative diagnosis as there was marked delay in the excision of such lesions.

  5. [False negatives and quality assurance in cervico-uterine cytology].

    PubMed

    Labbé, S; Petitjean, A

    1999-10-01

    Determining the false negative rate of cervical smear interpretation is an important part of quality assessment and a necessary step for any improvement program. We report our experience of negative smear rescreening of 522 histologically proven high-grade lesions or cancers, over a 5 to 7 year preceding period. False negative rate was 6.88% as calculated with a narrow definition of error, i.e. intra-epithelial lesions and atypical squamous cells of undetermined significance. It was 10.78% as calculated with a broad definition of error, including minor anomalies such as repair and parakeratosis. Bibliographic data account for 0 to 94% false negative diagnoses, owing to great disparities in calculating the false negative rate as well as in rescreening. However, a 10% traditionally calculated and standardised false negative rate is a reasonable and achievable goal in a view of quality improvement. Systematic random rescreening of 10% of negative smears is ineffective.

  6. A closer look at self-reported suicide attempts: false positives and false negatives.

    PubMed

    Plöderl, Martin; Kralovec, Karl; Yazdi, Kurosch; Fartacek, Reinhold

    2011-02-01

    The validity of self-reported suicide attempt information is undermined by false positives (e.g., incidences without intent to die), or by unreported suicide attempts, referred to as false negatives. In a sample of 1,385 Austrian adults, we explored the occurrence of false positives and false negatives with detailed, probing questions. Removing false positives decreased the rate of suicide attempters from 4.3% to 2.7%. Probing questions also revealed 0.8% false negatives. We recommend using probing questions with both those who report a suicide attempt and those who do not report a suicide attempt to increase the validity of self-reported suicide-related information.

  7. Linear filtering reveals false negatives in species interaction data

    PubMed Central

    Stock, Michiel; Poisot, Timothée; Waegeman, Willem; De Baets, Bernard

    2017-01-01

    Species interaction datasets, often represented as sparse matrices, are usually collected through observation studies targeted at identifying species interactions. Due to the extensive required sampling effort, species interaction datasets usually contain many false negatives, often leading to bias in derived descriptors. We show that a simple linear filter can be used to detect false negatives by scoring interactions based on the structure of the interaction matrices. On 180 different datasets of various sizes, sparsities and ecological interaction types, we found that on average in about 75% of the cases, a false negative interaction got a higher score than a true negative interaction. Furthermore, we show that this filter is very robust, even when the interaction matrix contains a very large number of false negatives. Our results demonstrate that unobserved interactions can be detected in species interaction datasets, even without resorting to information about the species involved. PMID:28383526

  8. Trade-off between false positives and false negatives in the linkage analysis of complex traits.

    PubMed

    Todorov, A A; Rao, D C

    1997-01-01

    This study examines the issue of false positives in genomic scans for detecting complex trait loci using subpair linkage methods and investigates the trade-off between the rate of false positives and the rate of false negatives. It highlights the tremendous cost in terms of power brought about by an excessive control of type I error and, at the same time, confirms that a larger number of false positives can occur otherwise in the course of a genomic scan. Finally, it compares the power and rate of false positives obtained in preplanned replicated studies conducted using a liberal significance level to those for single-step studies that use the same total sample size but stricter levels of significance. For the models considered here, replicate studies were found more attractive as long as one is willing to accept a trade-off, exchanging a much lower rate of false negatives for a slight increase in the rate of false positives.

  9. On False-Positive and False-Negative Decisions with a Mastery Test.

    ERIC Educational Resources Information Center

    Wilcox, Rand R.

    Wilcox (1977) examines two methods of estimating the probability of a false-positive on false-negative decision with a mastery test. Both procedures make assumptions about the form of the true score distribution which might not give good results in all situations. In this paper, upper and lower bounds on the two possible error types are described…

  10. False-positive and false-negative rates in meconium drug testing.

    PubMed

    Moore, C; Lewis, D; Leikin, J

    1995-11-01

    To determine the number of false-negative results produced by inefficient extraction of drugs from meconium, three published procedures were compared by using previously confirmed positive and negative meconium specimens. The methods were not equivalent in their ability to extract drugs from the matrix. To determine the number of false positives reported by the use of screen-only (unconfirmed) results, 535 screen-positive meconium specimens were subjects to confirmation by gas chromatography-mass spectrometry. Fifty-seven percent of the samples were confirmed positive for one or more of the drugs under investigation, showing that a false-positive rate as high as 43% may exist when unconfirmed screening results are used.

  11. High False Positives and False Negatives in Yeast Parameter in an Automated Urine Sediment Analyzer

    PubMed Central

    Aydin, Ozgur; Ellidag, Hamit Yasar; Eren, Esin; Yilmaz, Necat

    2015-01-01

    Summary Background Automated urine sediment analyzers have proven their feasibility in medical laboratories. However, editing manual microscopic review of some specimens severely limits the usefulness of such systems. This study aims to give feedback on the practical experience on »Yeast«, which is one of the parameters that compel frequent manual reviews. Methods 5448 freshly collected urine specimens submitted from various departments of our hospital for diagnostic urinalysis were studied by the UriSed® (77 Elektronika, Hungary). A specialist medical doctor inspected every image on-board, and reviewed the ones with a »Yeast« alarm by traditional manual microscopy. Results UriSed alarmed in 491 samples (9%) for yeast. In 59 samples (1%) the number of particles exceeded the cut-off and a »positive for yeast« was set. A false positive report of yeast +1 to 3+/HPF was found in 51 samples (0.9%). There were 8 cases with positive for yeast from both microscopic methods. Thirty-three »negative for yeast« samples were corrected as positive after the manual microscopic review. Conclusions We report a high percentage of false positives and negatives in the yeast parameter, in line with other studies on UriSed as well as on other instruments in the market. As an important feedback, our observations showed that the major concern in false results was »the focusing problem«. We believe in the necessity of a focus check and comparison of alarms between images on board. PMID:28356844

  12. False-negative results after stereotactically guided vacuum biopsy.

    PubMed

    Peter, D; Grünhagen, J; Wenke, R; Schäfer, F K W; Schreer, I

    2008-01-01

    The purpose of this study was to determine the false negative rate of stereotactically guided vacuum biopsy (VB). Data of patients with benign lesions in VB were evaluated retrospectively during a median follow-up period of 21 months. A total of 404 VB were considered benign and representative and were recommended for follow-up. Of these 404 lesions, 195 were completely removed radiologically. Follow-up data were available for 354/404 patients (87.6%), with intervals ranging from 3 to 66 months (median 21, mean 22.4). Reintervention or surgery was necessary in 13/354 (3.7%) cases. Of these cases, 5/354 (1.4%) turned out to be false negatives. Four of these cases showed large areas of microcalcifications or several clusters, and only partial removal was possible due to the size of the lesions. Although VB is an accurate procedure for diagnosing nonpalpable breast lesions with a low cancer miss rate, we consider the exclusion of malignancy in cases of disseminated microcalcifications or several clusters as a limitation. The radiologic-pathologic correlation in these cases is a challenge, particularly in terms of the residuals. Strict follow-up of benign lesions is essential to avoid delayed cancer diagnosis.

  13. Abort Trigger False Positive and False Negative Analysis Methodology for Threshold-Based Abort Detection

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.; Cruz, Jose A.; Johnson Stephen B.; Lo, Yunnhon

    2015-01-01

    This paper describes a quantitative methodology for bounding the false positive (FP) and false negative (FN) probabilities associated with a human-rated launch vehicle abort trigger (AT) that includes sensor data qualification (SDQ). In this context, an AT is a hardware and software mechanism designed to detect the existence of a specific abort condition. Also, SDQ is an algorithmic approach used to identify sensor data suspected of being corrupt so that suspect data does not adversely affect an AT's detection capability. The FP and FN methodologies presented here were developed to support estimation of the probabilities of loss of crew and loss of mission for the Space Launch System (SLS) which is being developed by the National Aeronautics and Space Administration (NASA). The paper provides a brief overview of system health management as being an extension of control theory; and describes how ATs and the calculation of FP and FN probabilities relate to this theory. The discussion leads to a detailed presentation of the FP and FN methodology and an example showing how the FP and FN calculations are performed. This detailed presentation includes a methodology for calculating the change in FP and FN probabilities that result from including SDQ in the AT architecture. To avoid proprietary and sensitive data issues, the example incorporates a mixture of open literature and fictitious reliability data. Results presented in the paper demonstrate the effectiveness of the approach in providing quantitative estimates that bound the probability of a FP or FN abort determination.

  14. Black and green tea - luminol false-negative bloodstains detection.

    PubMed

    Bancirova, Martina

    2012-06-01

    The antioxidant properties of black and green teas are well known. It is also possible to determine their antioxidant capacity by using a chemiluminscent method. This method is based on the measurement of the delay in the emission of light from the luminol reaction in the presence of the antioxidant. Bloodstains which are invisible to the naked eye can also be detected by luminol. Three common methods (detection using the Grodsky or Weber formulations and by Bluestar® Forensic latent bloodstain reagent) are based on the luminol chemiluminescence reaction. The bloodstains can be masked by drinks and/or foods containing antioxidants. The aim of this work was to compare the ability of black and green teas containing antioxidants to cause false negative results during chemiluminescent bloodstain detection.

  15. "False negatives" and "false positives" in acute pulmonary embolism: a clinical-postmortem comparison.

    PubMed

    Mandelli, V; Schmid, C; Zogno, C; Morpurgo, M

    1997-02-01

    Although recent advances have been made in understanding its epidemiology, diagnosis and treatment, pulmonary embolism (PE) is still largely undetected and untreated, and the mortality rate has not appreciably changed in the last decades. The aim of this study was to: compare the postmortem frequency of massive and sub-massive PE during two different time periods in the same general hospital; ascertain whether the percentage of correct clinical diagnosis of PE has changed; identify factors which might contribute to the inaccuracy of the clinical diagnosis of PE. Altogether, 288 patients with autopsy-proven PE and adequate clinical data were collected in the first period; 182 subjects with the same characteristics were found in the second period. Cases observed from 1989 through 1994 were evaluated in terms of frequency of false negatives and false positives, predictive value of the clinical diagnosis of PE, and correlations between clinical and post-mortem diagnosis of PE on one side and several independent variables such as age, gender, associated diseases, recent surgery on the other. In our hospital the frequency of massive and submassive PE at autopsy was 8.6% from 1966 through 1974, 12.6% from 1989 through 1994 (p < 0.01). The percentage of correct clinical diagnosis of PE was 19.6% in the former period, 21.6% in the latter (NS) with 78.57% of false negatives and only 1.73% of false positives. Altogether the true positives were 21.42%, most of them being patients with massive PE. Clinical findings showed the coexistence of heart disease in 51.6% of the cases, congestive heart failure in 20.15%, metabolic disease in 7%, stroke in 12.5%, recent surgery in 12.5%. Autopsy revealed the presence of pulmonary infarction in 22% of cases, malignancy in 24.0%, pneumonia in 17.05%, acute myocardial infarction in 14.8%. Seventy percent of the cases in whom the point of origin of thromboemboli could be demonstrated had one or more thrombus in the district of inferior vena

  16. Risk factors for false positive and for false negative test results in screening with fecal occult blood testing.

    PubMed

    Stegeman, Inge; de Wijkerslooth, Thomas R; Stoop, Esther M; van Leerdam, Monique; van Ballegooijen, M; Kraaijenhagen, Roderik A; Fockens, Paul; Kuipers, Ernst J; Dekker, Evelien; Bossuyt, Patrick M

    2013-11-15

    Differences in the risk of a false negative or a false positive fecal immunochemical test (FIT) across subgroups may affect optimal screening strategies. We evaluate whether subgroups are at increased risk of a false positive or a false negative FIT result, whether such variability in risk is related to differences in FIT sensitivity and specificity or to differences in prior CRC risk. Randomly selected, asymptomatic individuals were invited to undergo colonoscopy. Participants were asked to undergo one sample FIT and to complete a risk questionnaire. We identified patient characteristics associated with a false negative and false positive FIT results using logistic regression. We focused on statistically significant differences as well as on variables influencing the false positive or negative risk for which the odds ratio exceeded 1.25. Of the 1,426 screening participants, 1,112 (78%) completed FIT and the questionnaire; 101 (9.1%) had advanced neoplasia. 102 Individuals were FIT positive, 65 (64%) had a false negative FIT result and 66 (65%) a false positive FIT result. Participants at higher age and smokers had a significantly higher risk of a false negative FIT result. Males were at increased risk of a false positive result, so were smokers and regular NSAID users. FIT sensitivity was lower in females. Specificity was lower for males, smokers and regular NSAID users. FIT sensitivity was lower in women. FIT specificity was lower in males, smokers and regular NSAID users. Our results can be used for further evidence based individualization of screening strategies.

  17. Bayesian estimation of false-negative rate in a clinical trial of sentinel node biopsy.

    PubMed

    Newcombe, Robert G

    2007-08-15

    Estimating the false-negative rate is a major issue in evaluating sentinel node biopsy (SNB) for staging cancer. In a large multicentre trial of SNB for intra-operative staging of clinically node-negative breast cancer, two sources of information on the false-negative rate are available.Direct information is available from a preliminary validation phase: all patients underwent SNB followed by axillary nodal clearance or sampling. Of 803 patients with successful sentinel node localization, 19 (2.4 per cent) were classed as false negatives. Indirect information is also available from the randomized phase. Ninety-seven (25.4 per cent) of 382 control patients undergoing axillary clearance had positive axillae. In the experimental group, 94/366 (25.7 per cent) were apparently node positive. Taking a simple difference of these proportions gives a point estimate of -0.3 per cent for the proportion of patients who had positive axillae but were missed by SNB. This estimate is clearly inadmissible. In this situation, a Bayesian analysis yields interpretable point and interval estimates. We consider the single proportion estimate from the validation phase; the difference between independent proportions from the randomized phase, both unconstrained and constrained to non-negativity; and combined information from the two parts of the study. As well as tail-based and highest posterior density interval estimates, we examine three obvious point estimates, the posterior mean, median and mode. Posterior means and medians are similar for the validation and randomized phases separately and combined, all between 2 and 3 per cent, indicating similarity rather than conflict between the two data sources.

  18. [Nuclear morphology in false negative and negative rectal biopsies (author's transl)].

    PubMed

    Rilke, F; Clemente, C; Pilotti, S

    1975-01-01

    An typical nuclear structure consisting of a cribriform and condensed chromatin pattern with hyperchromasia, a small nucleolus and a moderately increased nuclear-cytoplasmic ratio was observed in the epithelial cells of the crypts and in the stromal and muscular cells of 51 out of 70 oncologically negative biopsies of the rectal mucosa. The subsequent retrieval of all clinical and histologia data revealed that the 51 cases included 39 of adenocarcinoma of the large intestine either present (15 cases) at a variable distance from the false negative biopsy or removed previously (24 cases), 7 of extra-intestinal malignant tumor (parotid gland, urinary bladder, endometrium, breast, stomach, metastatic, anus) and 5 with benign conditions of the large intestine. Of the remaining 19 cases whose biopsies did not reveal the atypical nuclear structure 16 had benign lesions of the large intestine and nowhere evidence of malignancy, two had an adenocarcinoma of the large bowel (one present and one removed previously) and one a carcinoma of the anus. In the rectal biopsies examined the atypical nuclear structure was detected in 93.9% of the cases with a malignant tumor either present or removed previously and in 19% of the cases with benign conditions. The morphologic evidence indicated that the atypical nuclear structure was compatible with a possible distrubance of the mitotic cycle since the findings were restricted to the generative compartment of rectal epithelium. The results are discussed in connection with their possible practical use as a diagnostic aid in the evaluation and interpretation of false negative and negative rectal biopsies as well as with their possible significance in the biology of tumor-bearing hosts.

  19. Using Sniffing Behavior to Differentiate True Negative from False Negative Responses in Trained Scent-Detection Dogs

    PubMed Central

    Mills, Daniel S.; Feugier, Alexandre; Zulch, Helen; Guest, Claire; Harris, Rob; Pike, Thomas W.

    2014-01-01

    False negatives are recorded in every chemical detection system, but when animals are used as a scent detector, some false negatives can arise as a result of a failure in the link between detection and the trained alert response, or a failure of the handler to identify the positive alert. A false negative response can be critical in certain scenarios, such as searching for a live person or detecting explosives. In this study, we investigated whether the nature of sniffing behavior in trained detection dogs during a controlled scent-detection task differs in response to true positives, true negatives, false positives, and false negatives. A total of 200 videos of 10 working detection dogs were pseudorandomly selected and analyzed frame by frame to quantify sniffing duration and the number of sniffing episodes recorded in a Go/No-Go single scent-detection task using an eight-choice test apparatus. We found that the sniffing duration of true negatives is significantly shorter than false negatives, true positives, and false positives. Furthermore, dogs only ever performed one sniffing episode towards true negatives, but two sniffing episodes commonly occurred in the other situations. These results demonstrate how the nature of sniffing can be used to more effectively assess odor detection by dogs used as biological detection devices. PMID:25214467

  20. Kinetic Evidence of an Apparent Negative Activation Enthalpy in an Organocatalytic Process

    PubMed Central

    Han, Xiao; Lee, Richmond; Chen, Tao; Luo, Jie; Lu, Yixin; Huang, Kuo-Wei

    2013-01-01

    A combined kinetic and computational study on our tryptophan-based bifunctional thiourea catalyzed asymmetric Mannich reactions reveals an apparent negative activation enthalpy. The formation of the pre-transition state complex has been unambiguously confirmed and these observations provide an experimental support for the formation of multiple hydrogen bonding network between the substrates and the catalyst. Such interactions allow the creation of a binding cavity, a key factor to install high enantioselectivity. PMID:23990028

  1. Improving Universal Suicide Prevention Screening in Primary Care by Reducing False Negatives

    DTIC Science & Technology

    2015-09-01

    negative rates; and (c) to systematically quantify false negative rates across various patient subgroups (e.g., gender , race, age, deployment history...5 5.1. Changes in approach and reasons for change ...5 5.3. Changes that had a significant impact on expenditures ............................................................... 6

  2. Sadder and Less Accurate? False Memory for Negative Material in Depression

    PubMed Central

    Joormann, Jutta; Teachman, Bethany A.; Gotlib, Ian H.

    2012-01-01

    Previous research has demonstrated that induced sad mood is associated with increased accuracy of recall in certain memory tasks; the effects of clinical depression, however, are likely to be quite different. We used the Deese-Roediger-McDermott (DRM) paradigm to examine the impact of clinical depression on erroneous recall of neutral and/or emotional stimuli. Specifically, we presented DRM lists that were highly associated with negative, neutral, or positive lures and compared participants diagnosed with Major Depressive Disorder (MDD) and nondepressed control (CTL) participants on the accuracy of their recall of presented material and their false recall of never-presented lures. Compared with CTL participants, MDD participants recalled fewer words that had been previously presented but were more likely to falsely recall negative lures; there were no differences between MDD and CTL participants in false recall of positive or neutral lures. These findings indicate that depression is associated with false memories of negative material. PMID:19413415

  3. A critical reappraisal of false negative sentinel lymph node biopsy in melanoma.

    PubMed

    Manca, G; Romanini, A; Rubello, D; Mazzarri, S; Boni, G; Chiacchio, S; Tredici, M; Duce, V; Tardelli, E; Volterrani, D; Mariani, G

    2014-06-01

    Lymphatic mapping and sentinel lymph node biopsy (SLNB) have completely changed the clinical management of cutaneous melanoma. This procedure has been accepted worldwide as a recognized method for nodal staging. SLNB is able to accurately determine nodal basin status, providing the most useful prognostic information. However, SLNB is not a perfect diagnostic test. Several large-scale studies have reported a relatively high false-negative rate (5.6-21%), correctly defined as the proportion of false-negative results with respect to the total number of "actual" positive lymph nodes. The main purpose of this review is to address the technical issues that nuclear physicians, surgeons, and pathologists should carefully consider to improve the accuracy of SLNB by minimizing its false-negative rate. In particular, SPECT/CT imaging has demonstrated to be able to identify a greater number of sentinel lymph nodes (SLNs) than those found by planar lymphoscintigraphy. Furthermore, a unique definition in the international guidelines is missing for the operational identification of SLNs, which may be partly responsible for this relatively high false-negative rate of SLNB. Therefore, it is recommended for the scientific community to agree on the radioactive counting rate threshold so that the surgeon can be better radioguided to detect all the lymph nodes which are most likely to harbor metastases. Another possible source of error may be linked to the examination of the harvested SLNs by conventional histopathological methods. A more careful and extensive SLN analysis (e.g. molecular analysis by RT-PCR) is able to find more positive nodes, so that the false-negative rate is reduced. Older age at diagnosis, deeper lesions, histologic ulceration, head-neck anatomical location of primary lesions are the clinical factors associated with false-negative SLNBs in melanoma patients. There is still much controversy about the clinical significance of a false-negative SLNB on the prognosis

  4. False-negative results for urinary phenothiazines and imipramine in Forrest's qualitative assays.

    PubMed

    James, G P; DJang, M H; Hamilton, H H

    1980-02-01

    When a series of patients' urine samples supplemented in vitro with chlorpromazine or imipramine was assayed with the Forrest qualitative assays, we observed an occasional false-negative result, which we found was attributable to interference by ascorbic acid. It interferes with the reagent, not with the analytes, in both assays. We easily eliminated this interference with the phenothiazine test by using an anion-exchange resin. Eliminating the interference with the assay for imipramine, however, is more difficult; false-negative results can be obtained even after ion-exchange chromatography if the imipramine concentration is less than 50 mg/L.

  5. Unexplained False Negative Results in Noninvasive Prenatal Testing: Two Cases Involving Trisomies 13 and 18

    PubMed Central

    Hochstenbach, R.; Page-Christiaens, G. C. M. L.; van Oppen, A. C. C.; Lichtenbelt, K. D.; van Harssel, J. J. T.; Brouwer, T.; Manten, G. T. R.; van Zon, P.; Elferink, M.; Kusters, K.; Akkermans, O.; Ploos van Amstel, J. K.; Schuring-Blom, G. H.

    2015-01-01

    Noninvasive prenatal testing (NIPT) validation studies show high sensitivity and specificity for detection of trisomies 13, 18, and 21. False negative cases have rarely been reported. We describe a false negative case of trisomy 13 and another of trisomy 18 in which NIPT was commercially marketed directly to the clinician. Both cases came to our attention because a fetal anatomy scan at 20 weeks of gestation revealed multiple anomalies. Karyotyping of cultured amniocytes showed nonmosaic trisomies 13 and 18, respectively. Cytogenetic investigation of cytotrophoblast cells from multiple placental biopsies showed a low proportion of nontrisomic cells in each case, but this was considered too small for explaining the false negative NIPT result. The discordant results also could not be explained by early gestational age, elevated maternal weight, a vanishing twin, or suboptimal storage or transport of samples. The root cause of the discrepancies could, therefore, not be identified. The couples involved experienced difficulties in accepting the unexpected and late-adverse outcome of their pregnancy. We recommend that all parties involved in caring for couples who choose NIPT should collaborate to clarify false negative results in order to unravel possible biological causes and to improve the process of patient care from initial counseling to communication of the result. PMID:26137330

  6. Risk of underdiagnosing amebic dysentery due to false-negative Entamoeba histolytica antigen detection.

    PubMed

    Prim, Núria; Escamilla, Pilar; Solé, Roser; Llovet, Teresa; Soriano, Germán; Muñoz, Carmen

    2012-08-01

    Entamoeba histolytica antigen assays on stool are widely used to diagnose amebiasis. We report a case of confirmed amebic colitis with a false-negative antigen detection that became positive after treatment. Our results indicate that these assays may underdiagnose acute amebic infection when used alone and should be used cautiously.

  7. Introducing Bayesian thinking to high-throughput screening for false-negative rate estimation.

    PubMed

    Wei, Xin; Gao, Lin; Zhang, Xiaolei; Qian, Hong; Rowan, Karen; Mark, David; Peng, Zhengwei; Huang, Kuo-Sen

    2013-10-01

    High-throughput screening (HTS) has been widely used to identify active compounds (hits) that bind to biological targets. Because of cost concerns, the comprehensive screening of millions of compounds is typically conducted without replication. Real hits that fail to exhibit measurable activity in the primary screen due to random experimental errors will be lost as false-negatives. Conceivably, the projected false-negative rate is a parameter that reflects screening quality. Furthermore, it can be used to guide the selection of optimal numbers of compounds for hit confirmation. Therefore, a method that predicts false-negative rates from the primary screening data is extremely valuable. In this article, we describe the implementation of a pilot screen on a representative fraction (1%) of the screening library in order to obtain information about assay variability as well as a preliminary hit activity distribution profile. Using this training data set, we then developed an algorithm based on Bayesian logic and Monte Carlo simulation to estimate the number of true active compounds and potential missed hits from the full library screen. We have applied this strategy to five screening projects. The results demonstrate that this method produces useful predictions on the numbers of false negatives.

  8. Case report: false negative serum cryptococcal latex agglutination test in a patient with disseminated cryptococcal disease.

    PubMed

    Navabi, Nazlee; Montebatsi, Milton; Scott, Michelle; Gluckman, Stephen J; Reid, Michael J A

    2015-01-01

    A case of false-negative serum latex agglutination cryptococcal antigen (CRAG) test in a 45-year-old HIV-positive male with Cryptococcus-positive culture is described. The patient was presented to a hospital in Botswana, with breathlessness and a diffuse papular rash. His CD4 count was 25 cells/μL. Despite the suspicion for disseminated cryptococcal disease, an initial serum CRAG latex test was negative. Results of subsequent Indian ink staining, culture of cerebrospinal fluid and skin scrapings, and serum lateral flow immunoassay (LFA) were all positive for Cryptococcus neoformans. There are several possible explanations for the false-negative CRAG latex test. Given the positive LFA result, we speculate that disease may have been caused by Cryptococcus gattii, which is estimated to be responsible for between 15% and 30% of all cryptococcal diseases in Botswana. Reduced sensitivity of CRAG latex assays for detecting C gattii may lead to underdiagnosis of cryptococcal infection.

  9. A Simple Strategy for Reducing False Negatives in Calling Variants from Single-Cell Sequencing Data

    PubMed Central

    Ji, Cong; Miao, Zong; He, Xionglei

    2015-01-01

    Due to the growth of interest in single-cell genomics, computational methods for distinguishing true variants from artifacts are highly desirable. While special attention has been paid to false positives in variant or mutation calling from single-cell sequencing data, an equally important but often neglected issue is that of false negatives derived from allele dropout during the amplification of single cell genomes. In this paper, we propose a simple strategy to reduce the false negatives in single-cell sequencing data analysis. Simulation results show that this method is highly reliable, with an error rate of 4.94×10-5, which is orders of magnitude lower than the expected false negative rate (~34%) estimated from a single-cell exome dataset, though the method is limited by the low SNP density in the human genome. We applied this method to analyze the exome data of a few dozen single tumor cells generated in previous studies, and extracted cell specific mutation information for a small set of sites. Interestingly, we found that there are difficulties in using the classical clonal model of tumor cell growth to explain the mutation patterns observed in some tumor cells. PMID:25876174

  10. A simple strategy for reducing false negatives in calling variants from single-cell sequencing data.

    PubMed

    Ji, Cong; Miao, Zong; He, Xionglei

    2015-01-01

    Due to the growth of interest in single-cell genomics, computational methods for distinguishing true variants from artifacts are highly desirable. While special attention has been paid to false positives in variant or mutation calling from single-cell sequencing data, an equally important but often neglected issue is that of false negatives derived from allele dropout during the amplification of single cell genomes. In this paper, we propose a simple strategy to reduce the false negatives in single-cell sequencing data analysis. Simulation results show that this method is highly reliable, with an error rate of 4.94×10-5, which is orders of magnitude lower than the expected false negative rate (~34%) estimated from a single-cell exome dataset, though the method is limited by the low SNP density in the human genome. We applied this method to analyze the exome data of a few dozen single tumor cells generated in previous studies, and extracted cell specific mutation information for a small set of sites. Interestingly, we found that there are difficulties in using the classical clonal model of tumor cell growth to explain the mutation patterns observed in some tumor cells.

  11. The Anterior Prefrontal Cortex and the Hippocampus Are Negatively Correlated during False Memories.

    PubMed

    Jeye, Brittany M; Karanian, Jessica M; Slotnick, Scott D

    2017-01-23

    False memories commonly activate the anterior/dorsolateral prefrontal cortex (A/DLPFC) and the hippocampus. These regions are assumed to work in concert during false memories, which would predict a positive correlation between the magnitudes of activity in these regions across participants. However, the A/DLPFC may also inhibit the hippocampus, which would predict a negative correlation between the magnitudes of activity in these regions. In the present functional magnetic resonance imaging (fMRI) study, during encoding, participants viewed abstract shapes in the left or right visual field. During retrieval, participants classified each old shape as previously in the "left" or "right" visual field followed by an "unsure"-"sure"-"very sure" confidence rating. The contrast of left-hits and left-misses produced two activations in the hippocampus and three activations in the left A/DLPFC. For each participant, activity associated with false memories (right-"left"-"very sure" responses) from the two hippocampal regions was plotted as a function of activity in each A/DLPFC region. Across participants, for one region in the left anterior prefrontal cortex, there was a negative correlation between the magnitudes of activity in this region and the hippocampus. This suggests that the anterior prefrontal cortex might inhibit the hippocampus during false memories and that participants engage either the anterior prefrontal cortex or the hippocampus during false memories.

  12. The Anterior Prefrontal Cortex and the Hippocampus Are Negatively Correlated during False Memories

    PubMed Central

    Jeye, Brittany M.; Karanian, Jessica M.; Slotnick, Scott D.

    2017-01-01

    False memories commonly activate the anterior/dorsolateral prefrontal cortex (A/DLPFC) and the hippocampus. These regions are assumed to work in concert during false memories, which would predict a positive correlation between the magnitudes of activity in these regions across participants. However, the A/DLPFC may also inhibit the hippocampus, which would predict a negative correlation between the magnitudes of activity in these regions. In the present functional magnetic resonance imaging (fMRI) study, during encoding, participants viewed abstract shapes in the left or right visual field. During retrieval, participants classified each old shape as previously in the “left” or “right” visual field followed by an “unsure”–“sure”–“very sure” confidence rating. The contrast of left-hits and left-misses produced two activations in the hippocampus and three activations in the left A/DLPFC. For each participant, activity associated with false memories (right–“left”–“very sure” responses) from the two hippocampal regions was plotted as a function of activity in each A/DLPFC region. Across participants, for one region in the left anterior prefrontal cortex, there was a negative correlation between the magnitudes of activity in this region and the hippocampus. This suggests that the anterior prefrontal cortex might inhibit the hippocampus during false memories and that participants engage either the anterior prefrontal cortex or the hippocampus during false memories. PMID:28124986

  13. False positives and false negatives in functional near-infrared spectroscopy: issues, challenges, and the way forward

    PubMed Central

    Tachtsidis, Ilias; Scholkmann, Felix

    2016-01-01

    Abstract. We highlight a significant problem that needs to be considered and addressed when performing functional near-infrared spectroscopy (fNIRS) studies, namely the possibility of inadvertently measuring fNIRS hemodynamic responses that are not due to neurovascular coupling. These can be misinterpreted as brain activity, i.e., “false positives” (errors caused by wrongly assigning a detected hemodynamic response to functional brain activity), or mask brain activity, i.e., “false negatives” (errors caused by wrongly assigning a not observed hemodynamic response in the presence of functional brain activity). Here, we summarize the possible physiological origins of these issues and suggest ways to avoid and remove them. PMID:27054143

  14. Preventing False Negatives for Histochemical Detection of Phenolics and Lignins in PEG-Embedded Plant Tissues.

    PubMed

    Ferreira, Bruno G; Falcioni, Renan; Guedes, Lubia M; Avritzer, Sofia C; Antunes, Werner C; Souza, Luiz A; Isaias, Rosy M S

    2017-02-01

    Polyethylene glycol (PEG) is a low-cost and advantageous embedding medium, which maintains the majority of cell contents unaltered during the embedding process. Some hard or complex plant materials are better embedded in PEG than in other usual embedding media. However, the histochemical tests for phenolics and lignins in PEG-embedded plant tissues commonly result in false negatives. We hypothesize that these false negatives should be prevented by the use of distinct fixatives, which should avoid the bonds between PEG and phenols. Novel protocols for phenolics and flavanols detection are efficiently tested, with fixation of the samples in ferrous sulfate and formalin or in caffeine and sodium benzoate, respectively. The differentiation of lignin types is possible in safranin-stained sections observed under fluorescence. The Maule's test faultlessly distinguishes syringyl-rich from guaiacyl- and hydroxyphenyl-rich lignins in PEG-embedded material under light microscopy. Current hypothesis is corroborated, that is, the adequate fixation solves the false-negative results, and the new proposed protocols fill up some gaps on the detection of phenolics and lignins.

  15. Rapid HIV testing for developing countries: the challenge of false-negative tests

    NASA Astrophysics Data System (ADS)

    Yogev, Ram

    2012-06-01

    It is a common practice in resource-constrained countries to accept two positive rapid HIV antibody test results as diagnostic for HIV infection. Because these tests are inexpensive and results are obtained quickly, they are recommended by the WHO to "scale-up" HIV testing to increase the number of people tested. The negative predictive value of rapid HIV tests is so high that negative results are considered conclusive despite the fact that false-negative results can occur in several situations. While the specificity and sensitivity of rapid HIV tests in resource-rich countries is acceptable, there are only limited data about their performance in resource-constrained countries. The challenges of rapid HIV testing in these situations will be discussed.

  16. A transfection reporter for the prevention of false-negative results in molecular beacon experiments.

    PubMed

    Toga, Tatsuya; Kuraoka, Isao; Yasui, Akira; Iwai, Shigenori

    2013-09-01

    We previously developed a molecular beacon-type probe to detect the strand scission in cellular base excision repair and found that the phosphodiester linkages in the fluorophore/quencher linkers were cleaved. This reaction was applied to a transfection reporter, which contained the unmodified phosphodiester in the linker to another type of fluorophore. After cotransfection of cells with the probe and the reporter, the signals were used to detect the incision and to confirm the proper transfection, respectively. This method will contribute to the prevention of false-negative results in experiments using molecular beacon-type probes.

  17. False-negative dipyridamole-thallium-201 myocardial imaging after caffeine infusion

    SciTech Connect

    Smits, P.; Corstens, F.H.; Aengevaeren, W.R.; Wackers, F.J.; Thien, T. )

    1991-08-01

    The vasodilator effect of intravenously administered dipyridamole may be caused by an increase in endogenous plasma adenosine levels. The authors evaluated the effect of caffeine, an adenosine receptor antagonist, on the diagnostic results of dipyridamole-201Tl myocardial imaging in eight patients with coronary artery disease. Caffeine infusion significantly attenuated the dipyridamole-induced fall in blood pressure and the accompanied increase in heart rate. The infusion of dipyridamole alone resulted in chest pain and ST-segment depressions on the electrocardiogram in four patients, whereas none of these problems occurred when the tests were repeated after caffeine. In six of eight patients, caffeine was responsible for false-negative dipyridamole-201Tl tests. Semiquantitive scores of the dipyridamole-induced 201Tl perfusion defects were decreased by caffeine from 9.0 {plus minus} 0.9 to 2.0 {plus minus} 1.1 points (p less than 0.05). Computerized analysis revealed a caffeine-mediated reduction in the percent reversibility of the images from 46% {plus minus} 16% to 6% {plus minus} 10% (p less than 0.05). They conclude that the use of caffeinated products prior to dipyridamole-201Tl testing may be responsible for false-negative findings.

  18. A new method with flexible and balanced control of false negatives and false positives for hit selection in RNA interference high-throughput screening assays.

    PubMed

    Zhang, Xiaohua Douglas

    2007-08-01

    The z-score method and its variants for testing mean difference are commonly used for hit selection in high-throughput screening (HTS) assays. Strictly standardized mean difference (SSMD) offers a way to measure and classify the short interfering RNA (siRNA) effects. In this article, based on SSMD, the authors propose a new testing method for hit selection in RNA interference (RNAi) HTS assays. This SSMD-based method allows the differentiation between siRNAs with large and small effects on the assay output and maintains flexible and balanced control of both the false-negative rate, in which the siRNAs with strong effects are not selected as hits, and the restricted false-positive rate, in which the siRNAs with weak or no effects are selected as hits. This method directly addresses the size of siRNA effects represented by the strength of difference between an siRNA and a negative reference, whereas the classic z-score method and t-test of testing no mean difference address whether the mean of an siRNA is exactly the same as the mean of a negative reference. This method can readily control the false-negative rate, whereas it is nontrivial for the classic z-score method and t-test to control the false-negative rate. Therefore, theoretically, the SSMD-based method offers better control of the sizes of siRNA effects and the associated false-positive and false-negative rates than the commonly used z-score method and t-test for hit selection in HTS assays. The SSMD-based method should generally be applicable to any assay in which the end point is a difference in signal compared to a reference sample, including those for RNAi, receptor, enzyme, and cellular function.

  19. Brain dead or not? CT angiogram yielding false-negative result on brain death confirmation.

    PubMed

    Johnston, Robyn; Kaliaperumal, Chandrasekaran; Wyse, Gerald; Kaar, George

    2013-01-08

    We describe a case of severe traumatic brain injury with multiple facial and skull fractures where CT angiogram (CTA) failed to yield a definite result of brain death as an ancillary test. A 28-year-old man was admitted following a road traffic accident with a Glasgow Coma Score (GCS) of 3/15 and fixed pupils. CT brain revealed uncal herniation and diffuse cerebral oedema with associated multiple facial and skull fractures. 72 h later, his clinical condition remained the same with high intracranial pressure refractory to medical management. Clinical confirmation on brain death was not feasible owing to facial injuries. A CTA, performed to determine brain perfusion, yielded a 'false-negative' result. Skull fractures have possibly led to venous prominence in the cortical and deep venous drainage system. This point needs to be borne in mind while considering CTA as an ancillary test to confirm brain death.

  20. Poor Cervical Cancer Screening Attendance and False Negatives. A Call for Organized Screening

    PubMed Central

    Castillo, Marta; Astudillo, Aurora; Clavero, Omar; Velasco, Julio; Ibáñez, Raquel; de Sanjosé, Silvia

    2016-01-01

    Objective The objective of this study was to describe prior negative screening history and symptoms around the time of diagnosis of incident cervical cancer (CC) cases diagnosed between 2000 and 2010 within the Asturias public health system. Methods Records from 374 women diagnosed with CC between 2000 and 2010 from all public hospitals in Asturias were retrieved. Clinical information, FIGO stage and all previous cytological data were extracted from clinical and histopathological records. Proportional differences were assessed using chi-square tests. Logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Inter-observer agreement in cytology was checked by comparing concordance values using k-statistics. Results No prior screening history was recorded in 60.7% of CC cases and its absence increased with age and advanced stage. Advanced stage (e.g., ≥ II) at diagnosis was associated with age (>50 years) and adenocarcinoma (ADC) compared to younger women and those with a squamous cell carcinoma (SCC). False negative smears were identified in 27.1% of women with CC (ADC 52.6% vs. SCC 16.2%, p<0.05). Conclusions Absence of prior screening history was common among CC cases. Organized actions to reduce “under screening” and the use of highly sensitive HPV-based tests could be useful strategies in reducing the burden of CC in Asturias. PMID:27547971

  1. Dimethoate affects cholinesterases in Folsomia candida and their locomotion--false negative results of an avoidance behaviour test.

    PubMed

    Pereira, Cecília M S; Novais, Sara C; Soares, Amadeu M V M; Amorim, Mónica J B

    2013-01-15

    The main mode of action of organophosphate insecticides is to inhibit acetylcholinesterase (AChE), which causes neuromuscular paralysis leading ultimately to death. The collembolan Folsomia candida is an important and standard test species in ecotoxicology, where effects on avoidance behaviour are assessed. Being related to insects they represent potential targets of insecticides such as the organophosphate dimethoate. In the present study we exposed F. candida to dimethoate having 2 main aims: 1) to assess the ability of F. candida to avoid it, and 2) to assess its effect on the cholinergic synapses to explore the link. For the latter, several sub-steps were needed: a) to characterise the existing ChE types and b) assess ChE activity (via exposure in vitro and in vivo). No avoidance was observed within the tested concentration range (0-0.32-1-3.2-10-32 mg/kg), in fact an apparent "attraction" (more animals on the spiked side) was observed. As expected, there was a significant decrease of AChE activities (AChE being the main ChE type) with an increase of dimethoate dose (IC(50)=1.4 mg/kg). Further, post-exposure video records showed that organisms were still alive in the spiked soil but lacked the locomotion ability (immobilised). The AChE inhibition correlated positively with immobilisation. Hence, this observation also showed that the apparent "attraction" behaviour observed in the avoidance test is rather a direct effect of not being able to escape due to paralysis hence a false-negative avoidance. This can constitute a confounding factor in an avoidance behaviour test and consequent interpretation, which is not accounted for at present.

  2. Acidic colonic microclimate--possible reason for false negative hydrogen breath tests.

    PubMed

    Vogelsang, H; Ferenci, P; Frotz, S; Meryn, S; Gangl, A

    1988-01-01

    About 5% of normal subjects fail to produce increased hydrogen breath concentration after ingestion of the non-digestible carbohydrate lactulose (low hydrogen producers). The existence of low hydrogen producers limits the diagnostic use of hydrogen (H2) breath tests. We studied the effects of lactulose and of magnesium sulphate (MgSO4) pretreatment on stool-pH and on hydrogen exhalation after oral loading with lactulose or lactose in 17 hydrogen producers and 12 low hydrogen producers. In seven hydrogen producers acidification of stool pH by lactulose pretreatment (20 g tid) decreased hydrogen exhalation and three of seven (43%) became low hydrogen producers. In contrast, after pretreatment of eight low hydrogen producers with magnesium sulphate (5 g twice daily) all eight produced hydrogen after a lactulose load. Similarly four lactose intolerant low hydrogen producers had abnormal lactose hydrogen breath tests after MgSO4 pretreatment. MgSO4 pretreatment neither resulted in false positive lactose hydrogen breath tests in five lactose tolerant hydrogen producers, nor increased the hydrogen exhalation in five additional hydrogen producing controls after ingestion of lactulose. The results of these studies confirm that hydrogen production from lactulose decreases when the colonic pH is lower (lactulose pretreatment), and increases when colonic pH is higher (MgSO4 pretreatment). In low hydrogen producers the lacking increase of H2 exhalation after ingestion of non-digestible carbohydrates can be overcome by MgSO4 pretreatment, thus increasing the sensitivity of the test by avoiding false negative hydrogen breath tests in low hydrogen producers with disaccharide malabsorption or maldigestion. The underlying mechanism of this remarkable effect of MgSO4 pretreatment warrants further investigation.

  3. False-Negative Rate and Recovery Efficiency Performance of a Validated Sponge Wipe Sampling Method

    SciTech Connect

    Krauter, Paula; Piepel, Gregory F.; Boucher, Raymond; Tezak, Matthew S.; Amidan, Brett G.; Einfeld, Wayne

    2012-02-01

    Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10x10^-3 to 1.86 CFU/cm^2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (>1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm^2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions.

  4. False-Negative Rate and Recovery Efficiency Performance of a Validated Sponge Wipe Sampling Method

    PubMed Central

    Piepel, Greg F.; Boucher, Raymond; Tezak, Matt; Amidan, Brett G.; Einfeld, Wayne

    2012-01-01

    Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10 × 10−3 to 1.86 CFU/cm2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (≥1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions. PMID:22138998

  5. Apparent Negative Reflection with the Gradient Acoustic Metasurface by Integrating Supercell Periodicity into the Generalized Law of Reflection.

    PubMed

    Liu, Bingyi; Zhao, Wenyu; Jiang, Yongyuan

    2016-12-05

    As the two dimensional version of the functional wavefront manipulation metamaterial, metasurface has become a research hot spot for engineering the wavefront at will with a subwavelength thickness. The wave scattered by the gradient metasurface, which is composed by the periodic supercells, is governed by the generalized Snell's law. However, the critical angle that derived from the generalized Snell's law circles the domain of the incident angles that allow the occurrence of the anomalous reflection and refraction, and no free space scattering waves could exist when the incident angle is beyond the critical angle. Here we theoretically demonstrate that apparent negative reflection can be realized by a gradient acoustic metasurface when the incident angle is beyond the critical angle. The underlying mechanism of the apparent negative reflection is understood as the higher order diffraction arising from the interaction between the local phase modulation and the non-local effects introduced by the supercell periodicity. The apparent negative reflection phenomena has been perfectly verified by the calculated scattered acoustic waves of the reflected gradient acoustic metasurface. This work may provide new freedom in designing functional acoustic signal modulation devices, such as acoustic isolator and acoustic illusion device.

  6. Apparent Negative Reflection with the Gradient Acoustic Metasurface by Integrating Supercell Periodicity into the Generalized Law of Reflection

    NASA Astrophysics Data System (ADS)

    Liu, Bingyi; Zhao, Wenyu; Jiang, Yongyuan

    2016-12-01

    As the two dimensional version of the functional wavefront manipulation metamaterial, metasurface has become a research hot spot for engineering the wavefront at will with a subwavelength thickness. The wave scattered by the gradient metasurface, which is composed by the periodic supercells, is governed by the generalized Snell’s law. However, the critical angle that derived from the generalized Snell’s law circles the domain of the incident angles that allow the occurrence of the anomalous reflection and refraction, and no free space scattering waves could exist when the incident angle is beyond the critical angle. Here we theoretically demonstrate that apparent negative reflection can be realized by a gradient acoustic metasurface when the incident angle is beyond the critical angle. The underlying mechanism of the apparent negative reflection is understood as the higher order diffraction arising from the interaction between the local phase modulation and the non-local effects introduced by the supercell periodicity. The apparent negative reflection phenomena has been perfectly verified by the calculated scattered acoustic waves of the reflected gradient acoustic metasurface. This work may provide new freedom in designing functional acoustic signal modulation devices, such as acoustic isolator and acoustic illusion device.

  7. Apparent Negative Reflection with the Gradient Acoustic Metasurface by Integrating Supercell Periodicity into the Generalized Law of Reflection

    PubMed Central

    Liu, Bingyi; Zhao, Wenyu; Jiang, Yongyuan

    2016-01-01

    As the two dimensional version of the functional wavefront manipulation metamaterial, metasurface has become a research hot spot for engineering the wavefront at will with a subwavelength thickness. The wave scattered by the gradient metasurface, which is composed by the periodic supercells, is governed by the generalized Snell’s law. However, the critical angle that derived from the generalized Snell’s law circles the domain of the incident angles that allow the occurrence of the anomalous reflection and refraction, and no free space scattering waves could exist when the incident angle is beyond the critical angle. Here we theoretically demonstrate that apparent negative reflection can be realized by a gradient acoustic metasurface when the incident angle is beyond the critical angle. The underlying mechanism of the apparent negative reflection is understood as the higher order diffraction arising from the interaction between the local phase modulation and the non-local effects introduced by the supercell periodicity. The apparent negative reflection phenomena has been perfectly verified by the calculated scattered acoustic waves of the reflected gradient acoustic metasurface. This work may provide new freedom in designing functional acoustic signal modulation devices, such as acoustic isolator and acoustic illusion device. PMID:27917909

  8. Technetium-99m white blood cell imaging: False-negative result in salmonella osteomyelitis associated with sickle cell disease

    SciTech Connect

    Guze, B.H.; Hawkins, R.A.; Marcus, C.S.

    1989-02-01

    The authors report a case of sickle cell anemia associated osteomyelitis where the Tc-99m white blood cell imaging was negative, and bone imaging showed increased uptake in the region in question. The reasons for the possible false-negative image are discussed.

  9. Negative affect promotes encoding of and memory for details at the expense of the gist: affect, encoding, and false memories.

    PubMed

    Storbeck, Justin

    2013-01-01

    I investigated whether negative affective states enhance encoding of and memory for item-specific information reducing false memories. Positive, negative, and neutral moods were induced, and participants then completed a Deese-Roediger-McDermott (DRM) false-memory task. List items were presented in unique spatial locations or unique fonts to serve as measures for item-specific encoding. The negative mood conditions had more accurate memories for item-specific information, and they also had fewer false memories. The final experiment used a manipulation that drew attention to distinctive information, which aided learning for DRM words, but also promoted item-specific encoding. For the condition that promoted item-specific encoding, false memories were reduced for positive and neutral mood conditions to a rate similar to that of the negative mood condition. These experiments demonstrated that negative affective cues promote item-specific processing reducing false memories. People in positive and negative moods encode events differently creating different memories for the same event.

  10. Molecular studies neglect apparently gram-negative populations in the human gut microbiota.

    PubMed

    Hugon, Perrine; Lagier, Jean-Christophe; Robert, Catherine; Lepolard, Catherine; Papazian, Laurent; Musso, Didier; Vialettes, Bernard; Raoult, Didier

    2013-10-01

    Studying the relationships between gut microbiota, human health, and diseases is a major challenge that generates contradictory results. Most studies draw conclusions about the gut repertoire using a single biased metagenomics approach. We analyzed 16 different stool samples collected from healthy subjects who were from different areas, had metabolic disorders, were immunocompromised, or were treated with antibiotics at the time of the stool collection. The analyses performed included Gram staining, flow cytometry, transmission electron microscopy (TEM), quantitative real-time PCR (qPCR) of the Bacteroidetes and Firmicutes phyla, and pyrosequencing of the 16S rRNA gene amplicons targeting the V6 region. We quantified 10(10) prokaryotes per gram of feces, which is less than was previously described. The Mann-Whitney test revealed that Gram-negative proportions of the prokaryotes obtained by Gram staining, TEM, and pyrosequencing differed according to the analysis used, with Gram-negative prokaryotes yielding median percentages of 70.6%, 31.0%, and 16.4%, respectively. A comparison of TEM and pyrosequencing analyses highlighted a difference of 14.6% in the identification of Gram-negative prokaryotes, and a Spearman test showed a tendency toward correlation, albeit not significant, in the Gram-negative/Gram-positive prokaryote ratio (ρ = 0.3282, P = 0.2146). In contrast, when comparing the qPCR and pyrosequencing results, a significant correlation was found for the Bacteroidetes/Firmicutes ratio (ρ = 0.6057, P = 0.0130). Our study showed that the entire diversity of the human gut microbiota remains unknown because different techniques generate extremely different results. We found that to assess the overall composition of bacterial communities, multiple techniques must be combined. The biases that exist for each technique may be useful in exploring the major discrepancies in molecular studies.

  11. On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis.

    PubMed

    Harrison, Hugo B; Saenz-Agudelo, Pablo; Planes, Serge; Jones, Geoffrey P; Berumen, Michael L

    2013-12-01

    Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses.

  12. Hypothetical explanations of the negative apparent effects of cloud seeding in the whitetop experiment.

    PubMed

    Lovasich, J L; Neyman, J; Scott, E L; Wells, M A

    1971-11-01

    In order to explain the apparent losses of rain ascribable to seeding at the Whitetop trial, particularly large and highly significant in the stratum E (but not in the opposite stratum W) of experimental days, it has been hypothesized that seeding causes widespread cloudiness and subsequent lowering of ground temperatures. This hypothesis is flatly contradicted by the observations: the seeded E-days (but not W-days) were uniformly less cloudy and hotter than those without seeding. Curiously, these differences prevailed not only from the scheduled time of seeding but also for several hours beforehand. The average rainfall for the 10 hr that preceded the time of seeding was investigated in eight "cells", defined by the day's wind direction to be downwind, upwind, and to the sides and "far" and "near" the center of seeding. Highly significant decreases were found in the far-upwind and far-left cells, indicating an earlymorning disparity between those E-days that later were declared as experimental to be seeded and those E-days that were declared as experimental not to be seeded. This disparity, difficult to explain by chance variation, suggests that particular caution be used in treating differences in the rainfall between seeded and not-seeded days in the Whitetop trial as having been caused by seeding.

  13. Classification of radiological errors in chest radiographs, using support vector machine on the spatial frequency features of false- negative and false-positive regions

    NASA Astrophysics Data System (ADS)

    Pietrzyk, Mariusz W.; Donovan, Tim; Brennan, Patrick C.; Dix, Alan; Manning, David J.

    2011-03-01

    Aim: To optimize automated classification of radiological errors during lung nodule detection from chest radiographs (CxR) using a support vector machine (SVM) run on the spatial frequency features extracted from the local background of selected regions. Background: The majority of the unreported pulmonary nodules are visually detected but not recognized; shown by the prolonged dwell time values at false-negative regions. Similarly, overestimated nodule locations are capturing substantial amounts of foveal attention. Spatial frequency properties of selected local backgrounds are correlated with human observer responses either in terms of accuracy in indicating abnormality position or in the precision of visual sampling the medical images. Methods: Seven radiologists participated in the eye tracking experiments conducted under conditions of pulmonary nodule detection from a set of 20 postero-anterior CxR. The most dwelled locations have been identified and subjected to spatial frequency (SF) analysis. The image-based features of selected ROI were extracted with un-decimated Wavelet Packet Transform. An analysis of variance was run to select SF features and a SVM schema was implemented to classify False-Negative and False-Positive from all ROI. Results: A relative high overall accuracy was obtained for each individually developed Wavelet-SVM algorithm, with over 90% average correct ratio for errors recognition from all prolonged dwell locations. Conclusion: The preliminary results show that combined eye-tracking and image-based features can be used for automated detection of radiological error with SVM. The work is still in progress and not all analytical procedures have been completed, which might have an effect on the specificity of the algorithm.

  14. False-negative rate of gram-stain microscopy for diagnosis of septic arthritis: suggestions for improvement.

    PubMed

    Stirling, Paul; Faroug, Radwane; Amanat, Suheil; Ahmed, Abdulkhaled; Armstrong, Malcolm; Sharma, Pankaj; Qamruddin, Ahmed

    2014-01-01

    We quantify the false-negative diagnostic rate of septic arthritis using Gram-stain microscopy of synovial fluid and compare this to values reported in the peer-reviewed literature. We propose a method of improving the diagnostic value of Gram-stain microscopy using Lithium Heparin containers that prevent synovial fluid coagulation. Retrospective study of the Manchester Royal Infirmary microbiology database of patients undergoing synovial fluid Gram-stain and culture between December 2003 and March 2012 was undertaken. The initial cohort of 1896 synovial fluid analyses for suspected septic arthritis was reduced to 143 after exclusion criteria were applied. Analysis of our Gram-stain microscopy yielded 111 false-negative results from a cohort size of 143 positive synovial fluid cultures, giving a false-negative rate of 78%. We report a false-negative rate of Gram-stain microscopy for septic arthritis of 78%. Clinicians should therefore avoid the investigation until a statistically significant data set confirms its efficacy. The investigation's value could be improved by using Lithium Heparin containers to collect homogenous synovial fluid samples. Ongoing research aims to establish how much this could reduce the false-negative rate.

  15. False-negative BD MGIT™ TBc Identification Test results in routine tuberculosis diagnosis: a New Zealand perspective.

    PubMed

    Basu, I; Bower, J E; Henderson, G K; Lowe, O; Newton, S; Vaughan, R; Roberts, S A

    2015-09-01

    >We previously reported on a comparison of the AccuProbe(®) Gen-Probe(®) MTBC assay (AccuProbe) (BioMérieux, Marcy L'Etoile, France) with the Becton Dickinson (BD) MGIT™ TBc Identification (TBc) Test (BD, Franklin Lakes, NJ, USA) in our laboratory. In the period following the shift from the AccuProbe assay to the TBc test, we obtained six false-negative results. On sequencing the mpt64 gene, we found that these false-negative cases had mutations in the mpt64 gene due to deletion, insertion or substitution. Despite the occurrence of false-negative results, we found that the reduced cost and minimal technical expertise, combined with a new testing algorithm, still make this test the preferred option for rapidly identifying Mycobacterium tuberculosis complex in MGIT cultures in a low TB burden country such as New Zealand.

  16. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    PubMed

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments.

  17. Background parenchymal enhancement at breast MR imaging: normal patterns, diagnostic challenges, and potential for false-positive and false-negative interpretation.

    PubMed

    Giess, Catherine S; Yeh, Eren D; Raza, Sughra; Birdwell, Robyn L

    2014-01-01

    At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imaging's diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation.

  18. Boronic Acid Group: A Cumbersome False Negative Case in the Process of Drug Design.

    PubMed

    Katsamakas, Sotirios; Papadopoulos, Anastasios G; Hadjipavlou-Litina, Dimitra

    2016-09-07

    Herein we present, an exhaustive docking analysis considering the case of autotaxin (ATX). HA155, a small molecule inhibitor of ATX, is co-crystallized. In order to further extract conclusions on the nature of the bond formed between the ligands and the amino acid residues of the active site, density functional theory (DFT) calculations were undertaken. However, docking does not provide reproducible results when screening boronic acid derivatives and their binding orientations to protein drug targets. Based on natural bond orbital (NBO) calculations, the formed bond between Ser/Thr residues is characterized more accurately as a polar covalent bond instead of a simple nonpolar covalent one. The presented results are acceptable and could be used in screening as an active negative filter for boron compounds. The hydroxyl groups of amino acids are bonded with the inhibitor's boron atom, converting its hybridization to sp³.

  19. The micronucleus test and NTP rodent carcinogens: not so many false negatives.

    PubMed

    Galloway, S M

    1996-06-10

    In the study by Shelby et al. (1993) on 49 chemicals, the results of the micronucleus (MN) test in mouse bone marrow were compared with the results of the 2 year rodent carcinogenicity assays. Seven of the 25 rodent carcinogens were considered positive in the MN test, 5 following a protocol in which chemicals were given in three daily doses, and a further 2 when the chemical was administered only once. This low rate of positive results has led to disappointment in the MN test as a screen for carcinogens, but a careful examination of the data and of its analysis by Shelby et al. (1993) shows that many of the negative results are appropriate because: of the 18 carcinogens that were negative in the MN test, 1 has been retested and found to be non-carcinogenic, 9 were non-genotoxic and at least 2 were site-of-contact carcinogens not expected to be detected in the bone marrow. Two others were clearly positive in the MN test in other labs. Thus, the MN test 'missed' not 18 carcinogens, but 4 genotoxic carcinogens. The significance of these 4 needs further assessment, since three were liver specific carcinogens and the fourth was a very weak inducer of hemangiosarcomas in female mice only. Overall, the results of Shelby et al. (1993) do not cast such a shadow on the micronucleus test as many feared, and must be examined in the context of all the information available on each chemical. As Ashby and Tinwell emphasize in the accompanying article and in Tinwell and Ashby (1994), the data show that the MN test is capable of identifying human carcinogens and rodent germ cell mutagens, and remains a useful part of genotoxicity evaluation of chemicals.

  20. Efficient information theoretic strategies for classifier combination, feature extraction and performance evaluation in improving false positives and false negatives for spam e-mail filtering.

    PubMed

    Zorkadis, V; Karras, D A; Panayotou, M

    2005-01-01

    Spam emails are considered as a serious privacy-related violation, besides being a costly, unsolicited communication. Various spam filtering techniques have been so far proposed, mainly based on Naïve Bayesian algorithms. Other Machine Learning algorithms like Boosting trees, or Support Vector Machines (SVM) have already been used with success. However, the number of False Positives (FP) and False Negatives (FN) resulting through applying various spam e-mail filters still remains too high and the problem of spam e-mail categorization cannot be solved completely from a practical viewpoint. In this paper, we propose a novel approach for spam e-mail filtering based on efficient information theoretic techniques for integrating classifiers, for extracting improved features and for properly evaluating categorization accuracy in terms of FP and FN. The goal of the presented methodology is to empirically but explicitly minimize these FP and FN numbers by combining high-performance FP filters with high-performance FN filters emerging from a previous work of the authors [Zorkadis, V., Panayotou, M., & Karras, D. A. (2005). Improved spam e-mail filtering based on committee machines and information theoretic feature extraction. Proceedings of the International Joint Conference on Neural Networks, July 31-August 4, 2005, Montreal, Canada]. To this end, Random Committee-based filters along with ADTree-based ones are efficiently combined through information theory, respectively. The experiments conducted are of the most extensive ones so far in the literature, exploiting widely accepted benchmarking e-mail data sets and comparing the proposed methodology with the Naive Bayes spam filter as well as with the Boosting tree methodology, the classification via regression and other machine learning models. It is illustrated by means of novel information theoretic measures of FP & FN filtering performance that the proposed approach is very favorably compared to the other rival methods

  1. False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

    PubMed Central

    2016-01-01

    Summary Osmium tetroxide 2,2’-bipyridine (OsBp) is known to react with pyrimidines in ssDNA and preferentially label deoxythymine (T) over deoxycytosine (C). The product, osmylated DNA, was proposed as a surrogate for nanopore-based DNA sequencing due to OsBp’s “perfect” label attributes. Osmylated deoxyoligos translocate unassisted and measurably slow via sub-2 nm SiN solid-state nanopores, as well as via the alpha-hemolysin (α-HL) pore. Both nanopores discriminate clearly between osmylated and intact nucleobase; α-HL was also shown to discriminate between osmylated T and osmylated C. Experiments presented here confirm that the kinetics of osmylation are comparable for short oligos and long ssDNA and show that pyrimidine osmylation is practically complete in two hours at room temperature with less than 15 mM OsBp. Under the proposed labeling conditions: deoxyoligo backbone degradation measures less than 1/1,000,000; false positives such as osmylated deoxyadenine (A) and osmylated deoxyguanine (G) measure less than 1/100,000; false negatives, i.e., unosmylated C measure less than 1/10,000; and unosmylated T must measure substantially lower than 1/10,000 due to the 27-fold higher reactivity of T compared to C. However, osmylated C undergoes degradation that amounts to about 1–2% for the duration of the labeling protocol. This degradation may be further characterized, possibly suppressed, and the properties of the degradation products via nanopore translocation can be evaluated to assure base calling quality in a DNA sequencing effort. PMID:27826518

  2. All That Glisters Is Not Gold: Sampling-Process Uncertainty in Disease-Vector Surveys with False-Negative and False-Positive Detections

    PubMed Central

    Abad-Franch, Fernando; Valença-Barbosa, Carolina; Sarquis, Otília; Lima, Marli M.

    2014-01-01

    Background Vector-borne diseases are major public health concerns worldwide. For many of them, vector control is still key to primary prevention, with control actions planned and evaluated using vector occurrence records. Yet vectors can be difficult to detect, and vector occurrence indices will be biased whenever spurious detection/non-detection records arise during surveys. Here, we investigate the process of Chagas disease vector detection, assessing the performance of the surveillance method used in most control programs – active triatomine-bug searches by trained health agents. Methodology/Principal Findings Control agents conducted triplicate vector searches in 414 man-made ecotopes of two rural localities. Ecotope-specific ‘detection histories’ (vectors or their traces detected or not in each individual search) were analyzed using ordinary methods that disregard detection failures and multiple detection-state site-occupancy models that accommodate false-negative and false-positive detections. Mean (±SE) vector-search sensitivity was ∼0.283±0.057. Vector-detection odds increased as bug colonies grew denser, and were lower in houses than in most peridomestic structures, particularly woodpiles. False-positive detections (non-vector fecal streaks misidentified as signs of vector presence) occurred with probability ∼0.011±0.008. The model-averaged estimate of infestation (44.5±6.4%) was ∼2.4–3.9 times higher than naïve indices computed assuming perfect detection after single vector searches (11.4–18.8%); about 106–137 infestation foci went undetected during such standard searches. Conclusions/Significance We illustrate a relatively straightforward approach to addressing vector detection uncertainty under realistic field survey conditions. Standard vector searches had low sensitivity except in certain singular circumstances. Our findings suggest that many infestation foci may go undetected during routine surveys, especially when vector

  3. False-negative indocyanine green videoangiography among complex unruptured middle cerebral artery aneurysms: the importance of further aneurysm inspection.

    PubMed

    Kulwin, Charles; Cohen-Gadol, Aaron A

    2014-10-01

    Successful surgical treatment of cerebral aneurysms requires complete occlusion of the aneurysm lumen while maintaining patency of the adjacent branching and perforating arteries. Intraoperative flow assessment allows aneurysm clip repositioning in the event these requirements are not met, avoiding the risk of postoperative rehemorrhage or infarction. A number of modalities have been proposed for primarily intraoperative qualitative blood flow assessment, including microdoppler ultrasonography, intraoperative digital subtraction angiography (DSA), and more recently noninvasive fluorescent angiography including indocyanine green (ICG) fluorescent imaging. Puncture of the aneurysm dome to exclude aneurysm sac filling may also assess the efficacy of clip placement. Although a high concordance between ICG and DSA has been reported, there remains an important subset of aneurysms for which negative ICG study may erroneously suggest aneurysm occlusion. A high-risk situation for such a false-negative study is an atherosclerotic middle cerebral artery (MCA) aneurysm in which vessel wall plaque interferes with the ICG signal. Furthermore, a decreased flow within the aneurysm may not allow enough emission light for detection under the current technology. In this report, we describe our experience with cases of MCA aneurysms with false-negative ICG-VA studies requiring clip adjustment for optimal surgical treatment and discuss two illustrative cases of MCA aneurysms with intraoperative fluorescence studies that were falsely negative, requiring puncture of the aneurysm to correctly identify incomplete aneurysm occlusion.

  4. An apparent-motion confound causes the negative exogenous cuing effect at SOAs with larger numbers of target locations.

    PubMed

    Chen, Peii; Mordkoff, J Toby

    2012-01-01

    Salient but irrelevant stimuli seem to cause an automatic orienting of covert attention, facilitating the detection of targets at the cued location for a brief period of time. However, this finding is highly dependent on the number of possible target locations, at least when the simple detection of targets is all that the task requires. Whereas small numbers of possible target locations (e.g., 2 or 3) produce the well-known advantage in response time for valid cue trials (i.e., a positive cuing effect), larger numbers of possible target locations (e.g., 6 or 8) produce a negative cuing effect. If not explained in terms of a nonattentional mechanism, this latter finding raises serious questions about the standard interpretation of positive cuing effects. The present experiment tested a particular nonattentional mechanism: that a confound between target presence and apparent motion, which occurs only on invalid cue trials, is responsible for negative cuing effect. We reduced or eliminated this confound by the use of a new type of catch trial and eliminated the negative cuing effect with large numbers of target locations.

  5. Diagnostic Bedside Vestibuloocular Reflex Evaluation in the Setting of a False Negative Fistula Test in Cholesteatoma of the Middle Ear

    PubMed Central

    Silveira, Ligia; Carmona, Sergio

    2017-01-01

    Background. False negative fistula testing in patients with chronic suppurative otitis media is a dilemma when proceeding to surgery. It is imperative to rule out a dead labyrinth or a mass effect secondary to the cholesteatoma in an otherwise normally functioning inner ear. We present a case series of three patients in whom a bedside vestibuloocular reflex (VOR) evaluation using a head impulse test was used successfully for further evaluation prior to surgery. Results. In all three cases with a false negative fistula test we were able to further evaluate at the bedside and were not only able to register the abnormal VOR but also localize its deterioration to a particular semicircular canal eroded by the fistula. Conclusion. Vestibuloocular reflex evaluation is mandatory in patients with suspected labyrinthine fistula due to cholesteatoma of the middle ear before proceeding to surgery. We demonstrate successful use of a bedside head impulse test for further evaluation prior to surgery in patients with false negative fistula test. PMID:28386500

  6. Balancing the false negative and positive rates in suspect screening with high-resolution Orbitrap mass spectrometry using multivariate statistics.

    PubMed

    Vergeynst, Leendert; Van Langenhove, Herman; Demeestere, Kristof

    2015-02-17

    Modern high-resolution mass spectrometry (HRMS) enables full-spectrum trace level analysis of emerging environmental organic contaminants. This raises the opportunity for post-acquisition suspect screening when no reference standards are a priori available. When setting up a conventional screening identification train based on successively different identification criteria including mass error and isotope fit, the false negative rate typically accumulates upon advancing through the decision tree. The challenge is thus to elaborate a well-balanced screening, in which the different criteria are equally stringent, leading to a controllable number of false negatives. Presented is a novel suspect screening approach using liquid-chromatography Orbitrap HRMS. Based on a multivariate statistical model, the screening takes into account the accurate mass error of the mono isotopic ion and up to three isotopes, isotope ratios, and a peak/noise filter. As such, for the first time, controlling the overall false negative rate of the screening algorithm to a desired level (5% in this study) is achieved. Simultaneously, a well-balanced identification decision is guaranteed taking the different identification criteria as a whole in a holistic statistical approach. Taking into account 1, 2, and 3 isotopes decreases the false positive rate from 22, 2.8 to <0.3%, but the cost of increasing the median limits of identification from 200, 2000 to 2062 ng L(-1), respectively, should also be considered. As proof of concept, 7 biologically treated wastewaters were screened toward 77 suspect pharmaceuticals resulting in the indicative identification of 25 suspects. Subsequently obtained reference standards allowed confirmation for 19 out of these 25 pharmaceutical contaminants.

  7. False negative PCR despite high levels of JC virus DNA in spinal fluid: Implications for diagnostic testing.

    PubMed

    Landry, Marie L; Eid, Tore; Bannykh, Serguei; Major, Eugene

    2008-10-01

    Genome amplification methods such as polymerase chain reaction (PCR) have revolutionized our ability to detect viruses in spinal fluids of patients with neurologic diseases. It is not as well appreciated among clinicians that PCR protocols, quality assurance, and technical expertise vary significantly among laboratories. In a multi-laboratory blinded study of herpes simplex virus PCR, the most widely used and best validated CSF PCR assay, low-level positives were often missed and false positives were not uncommon [Schloss L, van Loon AM, Cinque P, Cleator G, Echevarria JM, Falk KI, et al. An international external quality assessment of nucleic acid amplification of herpes simplex virus. J Clin Virol 2003;28(2):175-85]. In addition, genome variability and mutations, which are increasingly recognized for a number of different viruses, can lead to falsely low or negative results. Both clinicians and laboratories must recognize the limitations of PCR, since misleading results may have serious consequences. We present here a case of a rapidly progressive, fatal neurologic illness in a young mother, whose CSF JCV DNA PCR at a reference laboratory was falsely negative. Ultimately, brain biopsy established the diagnosis of progressive multifocal leukoencephalopathy (PML). Repeat PCR testing of the same CSF targeting a different region of the genome yielded a high positive result.

  8. Analysis of Current DNA Encoded Library Screening Data Indicates Higher False Negative Rates for Numerically Larger Libraries.

    PubMed

    Satz, Alexander L; Hochstrasser, Remo; Petersen, Ann C

    2017-03-17

    To optimize future DNA-encoded library design, we have attempted to quantify the library size at which the signal becomes undetectable. To accomplish this we (i) have calculated that percent yields of individual library members following a screen range from 0.002 to 1%, (ii) extrapolated that ∼1 million copies per library member are required at the outset of a screen, and (iii) from this extrapolation predict that false negative rates will begin to outweigh the benefit of increased diversity at library sizes >10(8). The above analysis is based upon a large internal data set comprising multiple screens, targets, and libraries; we also augmented our internal data with all currently available literature data. In theory, high false negative rates may be overcome by employing larger amounts of library; however, we argue that using more than currently reported amounts of library (≫10 nmoles) is impractical. The above conclusions may be generally applicable to other DNA encoded library platforms, particularly those platforms that do not allow for library amplification.

  9. Detectability of the Eurasian otter by standard surveys: an approach using marking intensity to estimate false negative rates.

    PubMed

    Balestrieri, Alessandro; Remonti, Luigi; Prigioni, Claudio

    2011-01-01

    False negative detections may bias the surveys for rare species and reduce the reliability of models based on the proportion of occupied patches. We assessed the detectability of the Eurasian otter Lutra lutra through the standard survey method by analysing the detection history of 28 sampling stretches surveyed monthly between March 2001 and January 2003. Each survey negative for otter spraints was considered as a false negative if the otter had been recorded in the previous and/or following month (respectively, cFN and FN). Otter marking intensity (MI) (MI=N° of spraints per kilometre) was calculated and assumed to represent an index of its relative abundance. Spraints were found in 81.7% of all surveys. Yearly MI ranged from 1.02 to 101.4 spraints per kilometre. In 2002, mean MI was significantly lower than in the previous year, while no clear seasonal trend could be outlined. The minimum number of surveys required to establish the occurrence of the otter, as estimated by a probability model, was 2.6 and was inversely related to MI. For a sub-sample of 18 sampling stretches, the relation between the frequency of both cFN and FN and five variables of potential interest for otters was tested by means of stepwise linear multiple regressions, yielding two highly significant models, which both included only MI as the explanatory variable. The frequency of both FN and cFN was correlated to MI and the resulting equations used to assess the percentage of surveys positive for otters in both years. After the correction for non-detections, otter site occupancy did not vary between the 2 years, except for one river when applying the more conservative estimate of false negatives (cFN). Multiple visits and the assessing of MI should become standard components of otter surveys. This approach has broad applicability and may be applied to assess the large-scale distribution of other rare or elusive mammalian carnivores.

  10. Detectability of the Eurasian otter by standard surveys: an approach using marking intensity to estimate false negative rates

    NASA Astrophysics Data System (ADS)

    Balestrieri, Alessandro; Remonti, Luigi; Prigioni, Claudio

    2011-01-01

    False negative detections may bias the surveys for rare species and reduce the reliability of models based on the proportion of occupied patches. We assessed the detectability of the Eurasian otter Lutra lutra through the standard survey method by analysing the detection history of 28 sampling stretches surveyed monthly between March 2001 and January 2003. Each survey negative for otter spraints was considered as a false negative if the otter had been recorded in the previous and/or following month (respectively, cFN and FN). Otter marking intensity (MI) (MI=N° of spraints per kilometre) was calculated and assumed to represent an index of its relative abundance. Spraints were found in 81.7% of all surveys. Yearly MI ranged from 1.02 to 101.4 spraints per kilometre. In 2002, mean MI was significantly lower than in the previous year, while no clear seasonal trend could be outlined. The minimum number of surveys required to establish the occurrence of the otter, as estimated by a probability model, was 2.6 and was inversely related to MI. For a sub-sample of 18 sampling stretches, the relation between the frequency of both cFN and FN and five variables of potential interest for otters was tested by means of stepwise linear multiple regressions, yielding two highly significant models, which both included only MI as the explanatory variable. The frequency of both FN and cFN was correlated to MI and the resulting equations used to assess the percentage of surveys positive for otters in both years. After the correction for non-detections, otter site occupancy did not vary between the 2 years, except for one river when applying the more conservative estimate of false negatives (cFN). Multiple visits and the assessing of MI should become standard components of otter surveys. This approach has broad applicability and may be applied to assess the large-scale distribution of other rare or elusive mammalian carnivores.

  11. Decreased microfilarial load and its effect on the calculation of prevalence and the rate of false negatives in the detection of onchocerciasis.

    PubMed

    Mullen, K; Prost, A

    1983-03-01

    It has been shown in the epidemiological evaluation of onchocerciasis that the method of taking two or more snips per person contains information about the probabilities of false negatives which can be extracted and used to improve the prevalence estimates. Using the method of maximum likelihood, one can obtain expressions for estimating the prevalence, adjusted for the false negatives, and for estimating the proportion of false negatives. The variances of all estimates are also available, making confidence interval estimation possible.

  12. Detection of in situ and invasive endocervical adenocarcinoma on ThinPrep Pap Test: Morphologic analysis of false negative cases

    PubMed Central

    Chaump, Michael; Pirog, Edyta C.; Panico, Vinicius J. A.; d Meritens, Alexandre Buckley; Holcomb, Kevin; Hoda, Rana

    2016-01-01

    Background: The goal of this study was to calculate the sensitivity and false negative (FN) rate of ThinPrep Pap Test (TPPT) and carefully analyze missed cases for educational purposes. Materials and Methods: Patients with histologically proven adenocarcinoma in-situ (AIS) or invasive endocervical adenocarcinoma (EAC) over a 17-year-period (1998-2015) were identified. The TPPT immediately preceding the histological diagnosis of AIS/ECA was designated as index Pap (IP). Paps up to 122 months before histologic diagnosis of AIS/ECA were considered for this study. All available negative and unsatisfactory TPPT were re-reviewed. Results: There were 78 patients with histologically-proven AIS (56) or ECA (22) with 184 TPPTs, and 95 of these TPPTs were abnormal. Of the abnormal cases, 55.7% TPPTs were diagnosed as endocervical cell abnormality (atypical endocervical cells/AIS/ECA). Notably, 44.2% of abnormal TPPTs were diagnosed as squamous cell abnormality (atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion/high grade squamous intraepithelial lesion). Including the diagnoses of squamous cell abnormality, the sensitivity of index TPPT for histologically-confirmed AIS/ECA was 88%. Eighty-eight of 184 TPPT, including 10 IP, were negative = 87, or unsatisfactory = 1. Forty-two of these slides were available for re-review. Upon review, 21 TPPT (50%) were confirmed negative and 21 TPPT (50%) were reclassified as abnormal = 20, or unsatisfactory = 1. Of the FN cases, the main difficulty in correct diagnosis was the presence of few diagnostic cell clusters which had less feathering, and consisted of smaller, rounder cells in small and tighter clusters, with nuclear overlap. In particular, nuclear overlap in three-dimensional groups precluded the accurate diagnosis. Rare FN cases showed squamous cell abnormality on re-review, and rare cases showed obscuring blood or inflammation. Conclusion: A significant proportion of AIS/EAC is

  13. False negative rate and other performance measures of a sponge-wipe surface sampling method for low contaminant concentrations.

    SciTech Connect

    Einfeld, Wayne; Krauter, Paula A.; Boucher, Raymond M.; Tezak, Mathew; Amidan, Brett G.; Piepel, Greg F.

    2011-05-01

    Recovery of spores from environmental surfaces is known to vary due to sampling methodology, techniques, spore size and characteristics, surface materials, and environmental conditions. A series of tests were performed to evaluate a new, validated sponge-wipe method. Specific factors evaluated were the effects of contaminant concentrations and surface materials on recovery efficiency (RE), false negative rate (FNR), limit of detection (LOD) - and the uncertainties of these quantities. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show a roughly linear dependence of surface roughness on RE, where the smoothest surfaces have the highest mean RE values. REs were not influenced by the low spore concentrations tested (3 x 10{sup -3} to 1.86 CFU/cm{sup 2}). The FNR data were consistent with RE data, showing a trend of smoother surfaces resulting in higher REs and lower FNRs. Stainless steel generally had the lowest mean FNR (0.123) and plastic had the highest mean FNR (0.479). The LOD{sub 90} varied with surface material, from 0.015 CFU/cm{sup 2} on stainless steel up to 0.039 on plastic. Selecting sampling locations on the basis of surface roughness and using roughness to interpret spore recovery data can improve sampling. Further, FNR values, calculated as a function of concentration and surface material, can be used pre-sampling to calculate the numbers of samples for statistical sampling plans with desired performance, and post-sampling to calculate the confidence in characterization and clearance decisions.

  14. Tracking false-negative results in molecular diagnosis: proposal of a triplex-PCR based method for leishmaniasis diagnosis

    PubMed Central

    2014-01-01

    Background Molecular biological methods have become increasingly relevant to the diagnosis and control of infectious diseases, such as leishmaniasis. Since various factors may affect the sensitivity of PCR assays, including DNA yield and purity, an optimal extraction method is pivotal. Losses of a parasite’s DNA during extraction may significantly impair its detection by PCR and lead to false-negative results. This study proposes a triplex PCR assay targeting the parasite’s DNA, an external control (pUC18) and an internal control (G3PD) for accurate diagnosis of leishmaniasis. Results Two primer pairs were designed to detect the plasmid pUC18 and a triplex PCR assay targeting the Leishmania braziliensis kinetoplast DNA, the external control and the internal control was standardized. The triplex PCR assay was assessed for its ability to detect the three target DNA fragments simultaneously. PCR products from pUC18 DNA resulted in bands of 368 (P1) and 316 (P2) base pairs (bp). The triplex PCR optimized with the chosen external control system (P1) allowed the simultaneous detection of the internal control (G3PD – 567 bp) as well as of small quantities (10 pg) of the target parasite’s DNA, detected by amplification of a 138 bp product. Conclusions The new tool standardized herein enables a more reliable interpretation of PCR results, mainly by contributing to quality assurance of leishmaniasis diagnosis. Furthermore, after simple standardization steps, this protocol could be applied to the diagnosis of other infectious diseases in reference laboratories. This triplex PCR enables the assessment of small losses during the DNA extraction process, problems concerning DNA degradation (sample quality) and the detection of L. braziliensis kDNA. PMID:24808911

  15. EGFR mutation specific immunohistochemistry is a useful adjunct which helps to identify false negative mutation testing in lung cancer.

    PubMed

    Houang, Michelle; Sioson, Loretta; Clarkson, Adele; Watson, Nicole; Farzin, Mahtab; Toon, Christopher W; Raut, Aditi; O'Toole, Sandra A; Cooper, Wendy A; Pavlakis, Nick; Mead, Scott; Chou, Angela; Gill, Anthony J

    2014-10-01

    Mutations in EGFR guide treatment in non-small cell lung cancer (NSCLC). The most common mutations, exon 19 (delE746-A750) and exon 21 (L858R), can be identified by mutation specific immunohistochemistry (IHC). We present our prospective experience of universal reflex IHC and molecular testing in non-squamous NSCLC in the routine clinical setting.A total of 411 specimens from 332 patients were encountered over two years. Of these, 326 (98%) patients underwent EGFR IHC, 15 (5%) were positive for exon 19 deletions and 27 (8%) for exon 21 (L858R); 244 (73%) patients underwent molecular testing. Seventy-six mutations in 64 patients (19% of all patients encountered; 26% with sufficient material for testing) were identified. These comprised nine exon 18 (G719X) mutations, three also with exon 20 mutations; 24 exon 19 deletions, six also with exon 20 mutations; 23 exon 21 (L858R), three also with exon 20 mutations; and 8 exon 20 alone.All 15 exon 19 IHC positive patients were proven mutated (100% specificity, 63% sensitivity). Twenty-two of 27 exon 21 IHC positive cases were proven mutated while three patients had insufficient material for molecular testing (92% specificity, 96% sensitivity). The overall specificity and sensitivity of IHC for any EGFR mutation was 95% and 58%. Five patients initially thought to be wild type for EGFR but IHC positive underwent repeat molecular testing because of the discrepancy which confirmed the IHC result in three cases (60%).We conclude IHC is very specific but not sensitive. Whilst IHC cannot replace molecular testing, it is a useful adjunct which requires minimal tissue and identifies false negative molecular results which occurred in 5% of our patients with eventually confirmed EGFR mutations.

  16. False-negative cerebrospinal fluid cryptococcal antigen test due to small-colony variants of Cryptococcus neoformans meningitis in a patient with cystopleural shunt.

    PubMed

    To, Kelvin K W; Cheng, Vincent C C; Tang, Bone S F; Fan, Yiu-Wah; Yuen, Kwok-Yung

    2006-01-01

    This is the first report of a small-colony variant Cryptococcus neoformans isolated from the cerebrospinal fluid of a patient with cystopleural shunt associated chronic meningitis. Cryptococcal antigen testing of the cerebrospinal fluid and the serum were both negative. The atypical morphology and the false-negative test may lead to delay of diagnosis and treatment.

  17. Effects of Maternal Negativity and of Early and Recent Recurrent Depressive Disorder on Children's False Belief Understanding

    ERIC Educational Resources Information Center

    Rohrer, Lisa M.; Cicchetti, Dante; Rogosch, Fred A.; Toth, Sheree L.; Maughan, Angeline

    2011-01-01

    Research has shown that children of depressed mothers are at risk for problems in a variety of developmental domains; however, little is known about the effects of maternal depression on children's emerging understanding of false beliefs. In this study, 3 false belief tasks were administered to 5-year-old children whose mothers had either met…

  18. Serum Free Light Chain Assay and κ/λ Ratio: Performance in Patients With Monoclonal Gammopathy-High False Negative Rate for κ/λ Ratio

    PubMed Central

    Singh, Gurmukh

    2017-01-01

    Background Serum free light chain assay (SFLCA) and κ/λ ratio, and protein electrophoretic methods are used in the diagnosis and monitoring of monoclonal gammopathies. Methods Results for serum free light chains, serum and urine protein electrophoreses and immunofixation electrophoreses in 468 patients with a diagnosis of monoclonal gammopathy were compared. The results of the two methods were graded as concordant, non-concordant or discordant with the established diagnoses to assess the relative performance of the methods. Results of κ/λ ratio in samples with monoclonal protein detectable by electrophoretic methods were also analyzed. Results Protein electrophoreses results were concordant with the established diagnoses significantly more often than κ/λ ratio. The false negative rate for κ/λ ratio was higher than that for electrophoretic methods. κ/λ ratio was falsely negative in about 27% of the 1,860 samples with detectable monoclonal immunoglobulin. The false negative rate was higher in lesions with lambda chains (32%) than those with kappa chains (24%). The false negative rate for κ/λ ratio was over 55% in samples with monoclonal gammopathy of undetermined significance. Even at first encounter, the false negative rates for κ/λ ratios for monoclonal gammopathy of undetermined significance, smoldering myeloma and multiple myeloma were 66.98%, 23.08%, and 30.15%, respectively, with false negative rate for lambda chain lesions being higher. Conclusions Electrophoretic studies of serum and urine are superior to SFLCA and κ/λ ratio. Abnormal κ/λ ratio, per se, is not diagnostic of monoclonal gammopathy. A normal κ/λ ratio does not exclude monoclonal gammopathy. False negative rates for lesions with lambda chain are higher than those for lesions with kappa chains. Electrophoretic studies of urine are underutilized. Clinical usefulness and medical necessity of SFLCA and κ/λ ratio is of questionable value in routine clinical testing. PMID:27924175

  19. Warm Autoimmune Hemolytic Anemia and Direct Antiglobulin Testing With a False-Negative Result in a 53-Year-Old Man: The DAT Will Set You Free.

    PubMed

    Losos, Michael; Hamad, Diane; Joshi, Sarita; Scrape, Scott; Chen, Jian

    2016-08-01

    Warm autoimmune hemolytic anemia (WAIHA), the most common of the relatively uncommon autoimmune-mediated hemolytic anemias (AIHAs), is mediated by polyclonal immunoglobulin (Ig)G autoantibodies in most cases. Herein, we present a case of WAIHA involving a direct antiglobulin test (DAT) with an initially negative result. Using a modified DAT protocol, repeat testing of the same specimen material from a previously healthy 53-year-old man yielded positive results. This case demonstrates that investigation of an apparently negative DAT result plays a critical role in the differential diagnosis of patients with rapidly progressing hemolytic anemia and the reversal of that decline.

  20. Dogs cannot bark: event-related brain responses to true and false negated statements as indicators of higher-order conscious processing.

    PubMed

    Herbert, Cornelia; Kübler, Andrea

    2011-01-01

    The present study investigated event-related brain potentials elicited by true and false negated statements to evaluate if discrimination of the truth value of negated information relies on conscious processing and requires higher-order cognitive processing in healthy subjects across different levels of stimulus complexity. The stimulus material consisted of true and false negated sentences (sentence level) and prime-target expressions (word level). Stimuli were presented acoustically and no overt behavioral response of the participants was required. Event-related brain potentials to target words preceded by true and false negated expressions were analyzed both within group and at the single subject level. Across the different processing conditions (word pairs and sentences), target words elicited a frontal negativity and a late positivity in the time window from 600-1000 msec post target word onset. Amplitudes of both brain potentials varied as a function of the truth value of the negated expressions. Results were confirmed at the single-subject level. In sum, our results support recent suggestions according to which evaluation of the truth value of a negated expression is a time- and cognitively demanding process that cannot be solved automatically, and thus requires conscious processing. Our paradigm provides insight into higher-order processing related to language comprehension and reasoning in healthy subjects. Future studies are needed to evaluate if our paradigm also proves sensitive for the detection of consciousness in non-responsive patients.

  1. Sentinel lymph node biopsy after neo-adjuvant chemotherapy in patients with breast cancer: Are the current false negative rates acceptable?

    PubMed

    Patten, D K; Zacharioudakis, K E; Chauhan, H; Cleator, S J; Hadjiminas, D J

    2015-08-01

    The advent of sentinel lymph node biopsy has revolutionised surgical management of axillary nodal disease in patients with breast cancer. Patients undergoing neo-adjuvant chemotherapy for large breast primary tumours may experience complete pathological response on a previously positive sentinel node whilst not eliminating the tumour from the other lymph nodes. Results from 2 large prospective cohort studies investigating sentinel lymph node biopsy after neo-adjuvant chemotherapy demonstrate a combined false negative rate of 12.6-14.2% and identification rate of 80-89% with the minimal acceptable false negative rate and identification rate being set at 10% and 90%, respectively. A false negative rate of 14% would have been classified as unacceptable when compared to the figures obtained by the pioneers of sentinel lymph node biopsy which was 5% or less.

  2. Rectal culture screening for vancomycin-resistant enterococcus in chronic haemodialysis patients: false-negative rates and duration of colonisation.

    PubMed

    Park, I; Park, R W; Lim, S-K; Lee, W; Shin, J S; Yu, S; Shin, G-T; Kim, H

    2011-10-01

    Infection or colonisation with vancomycin-resistant enterococci (VRE) is common in chronic haemodialysis (HD) patients. However, there is limited information on the duration of VRE colonisation or on the reliability of consecutive negative rectal cultures to determine the clearance of VRE in chronic HD patients. Chronic HD patients from whom VRE was isolated were examined retrospectively. Rectal cultures were collected more than three times, at least one week apart, between 1 June 2003 and 1 March 2010. The results of the sequential VRE cultures and patients' data were analysed. Among 812 patients from whom VRE was isolated, 89 were chronic HD patients and 92 had three consecutive negative cultures. It took 60.7 ± 183.9 and 111.4 ± 155.4 days to collect three consecutive negative cultures in the 83 non-chronic haemodialysis patients and nine chronic HD patients, respectively (P = 0.011). The independent risk factors for more than three negative sequential rectal cultures were glycopeptide usage [odds ratio (OR): 2.155; P = 0.003] and length of hospital stay (OR: 1.009; P = 0.001). After three consecutive negative rectal cultures, two of six chronic HD patients and 10 of 36 non-HD patients were culture positive again. In conclusion, a significant proportion of patients colonised with VRE cannot be detected by three-weekly rectal cultures, and the duration of VRE colonisation in chronic haemodialysis patients tends to be prolonged. These results may be contributing to the continued increase in the prevalence of VRE.

  3. FALSE-NEGATIVE DENGUE CASES IN RORAIMA, BRAZIL: AN APPROACH REGARDING THE HIGH NUMBER OF NEGATIVE RESULTS BY NS1 AG KITS

    PubMed Central

    Acosta, Pablo O. A.; Granja, Fabiana; Meneses, Cátia A.; Nascimento, Ismael A. S.; Sousa, Débora D.; Lima, Wilson P.; Naveca, Felipe Gomes

    2014-01-01

    Serum samples from 150 NS1-negative (Platelia ELISA) patients presumptively diagnosed with dengue were analyzed by the TaqMan probed real-time reverse transcription PCR (TaqMan qRT-PCR) method. The qRT-PCR positive samples were tested for serotype by semi-nested RT-PCR and a qualitative immunochromatographic assay for IgG and IgM. Molecular detection methods showed 33 (22%) positive samples out of 150 NS1-antigen negative samples. Of these, 72% were collected up to day 2 after the onset of symptoms, when diagnostic sensitivity of NS1-antigen test assays is significantly enhanced. Most of the cases were not characterized as secondary infection. Twenty-eight samples were successfully serotyped, 75% of which for DENV-4, 14% for DENV-2, 7% for DENV-3 and 4% for DENV-1. These findings reaffirm the hyperendemic situation of the state of Roraima and suggest a lower sensitivity of the NS1 test, mainly when DENV-4 is the predominant serotype. Health care providers should therefore be aware of samples tested negative by NS1 antigen assays, especially when clinical symptoms and other laboratory data results show evidence of dengue infection. PMID:25229228

  4. Case Report of False-Negative Diffusion-Weighted Image of Brain Magnetic Resonance Imaging (MRI) in Acute Ischemic Stroke

    PubMed Central

    Chang, Wei-Lun; Lai, Ji-Ching; Chen, Rong-Fu; Hu, Han-Hwa; Pan, Chau-Shiung

    2017-01-01

    Patient: Male, 75 Final Diagnosis: Acute ischemic stroke Symptoms: Dizziness • unsteady gait Medication: — Clinical Procedure: None Specialty: Radiology Objective: Challenging differential diagnosis Background: Acute ischemic stroke is a major cause of mortality and morbidity in Taiwan. Diffusion-weighted image (DWI) is a sensitive and common strategy used for imaging acute ischemic stroke. Case report: We present a case of a negative DWI MRI for detecting acute ischemic stroke in a clinical setting. A 75-year-old male had a DWI performed after onset of symptoms suggesting acute ischemic stroke. The initial DWI result was negative at 72 hours of presentation. The neurological symptoms of the patient persisted and DWI was repeated. After 14 days, the DWI data confirmed and demonstrated an acute ischemic stroke. The delay in DWI confirmation, from symptom onset until DWI diagnosis, was 336 hours. Conclusions: DWI may not have 100% sensitivity and accuracy in early stages of acute ischemic stroke. The time course to the development of abnormalities detected by DWI may be longer than anticipated. PMID:28111452

  5. Serum albumin and globulin analysis for hepatocellular carcinoma detection avoiding false-negative results from alpha-fetoprotein test negative subjects

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Feng, Shangyuan; Lin, Juqiang; Zeng, Yongyi; Li, Ling; Huang, Zufang; Li, Buhong; Zeng, Haishan; Chen, Rong

    2013-11-01

    Surface-enhanced Raman spectroscopy (SERS) of serum albumin and globulin were employed to detect hepatocellular carcinoma (HCC). Tentative assignments of SERS bands show specific biomolecular changes associated with cancer development. These changes include a decrease in relative amounts of tryptophan, glutamine, glycine, and serine, indicating excessive consumption of amino acids for protein duplication. Principal component analysis was also introduced to analyze the obtained spectra, resulting in both diagnostic sensitivity and specificity of 100%. More importantly, it reveals that this method can detect HCC patients with alpha-fetoprotein negative test results, suggesting its great potential as a new alternative to detect HCC.

  6. False negative result for amphetamines on the Triage Drug of Abuse panel? The cause of the unusual phenomenon with experimental analyses.

    PubMed

    Hikiji, Wakako; Kudo, Keiko; Sato, Shinji; Usumoto, Yosuke; Tsuji, Akiko; Ikeda, Noriaki

    2009-05-01

    On-site drug screening devices are widely used today for their simple test procedures and instantaneous results. Among other devices, a Triage Drug of Abuse panel is considered to be highly reliable for its high specificity and sensitivity of abused drugs. Although it is known that a false positive amphetamine (AMP) result may be obtained from the urine samples containing putrefactive amines or ephedrine-related compounds, no clinical false negative methamphetamine results have been reported to date. However, a false negative Triage result was obtained from the urine of a fatal methamphetamine poisoning victim taking Vegetamine tablets. Further experimental analyses revealed that the cross-reactivity of methamphetamine and chlorpromazine metabolites, including nor-2-chlorpromazine sulfoxide, was the cause for a false negative Triage reaction for AMP. Forensic scientists and clinicians must be aware of the limitations of on-site drug testing devices and the need for the confirmatory laboratory tests for the precise identification and quantification of drugs in suspicious intoxication cases, as also recommended by the manufacturers.

  7. Experimental Design for a Macrofoam-Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

    SciTech Connect

    Piepel, Gregory F.; Hutchison, Janine R.

    2014-12-05

    This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam-swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (culture and polymerase chain reaction) will be used. Only one previous study has investigated how the false negative rate depends on test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gaps in the available information on the performance of macrofoam-swab sampling at low concentrations.

  8. Experimental Design for a Macrofoam Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

    SciTech Connect

    Piepel, Gregory F.; Hutchison, Janine R.

    2014-04-16

    This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (plating/counting and polymerase chain reaction) will be used. Only one previous study has investigated false negative as a function of affecting test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gaps in the available information on the performance of macrofoam swab sampling at low concentrations.

  9. Confidence interval for rate ratio in a 2 x 2 table with structural zero: an application in assessing false-negative rate ratio when combining two diagnostic tests.

    PubMed

    Tang, Man-Lai; Tang, Nian-Sheng; Carey, Vincent J

    2004-06-01

    In this article, we consider problems with correlated data that can be summarized in a 2 x 2 table with structural zero in one of the off-diagonal cells. Data of this kind sometimes appear in infectious disease studies and two-step procedure studies. Lui (1998, Biometrics54, 706-711) considered confidence interval estimation of rate ratio based on Fieller-type, Wald-type, and logarithmic transformation statistics. We reexamine the same problem under the context of confidence interval construction on false-negative rate ratio in diagnostic performance when combining two diagnostic tests. We propose a score statistic for testing the null hypothesis of nonunity false-negative rate ratio. Score test-based confidence interval construction for false-negative rate ratio will also be discussed. Simulation studies are conducted to compare the performance of the new derived score test statistic and existing statistics for small to moderate sample sizes. In terms of confidence interval construction, our asymptotic score test-based confidence interval estimator possesses significantly shorter expected width with coverage probability being close to the anticipated confidence level. In terms of hypothesis testing, our asymptotic score test procedure has actual type I error rate close to the pre-assigned nominal level. We illustrate our methodologies with real examples from a clinical laboratory study and a cancer study.

  10. RBM10-TFE3 Renal Cell Carcinoma: A Potential Diagnostic Pitfall Due to Cryptic Intrachromosomal Xp11.2 Inversion Resulting in False-negative TFE3 FISH.

    PubMed

    Argani, Pedram; Zhang, Lei; Reuter, Victor E; Tickoo, Satish K; Antonescu, Cristina R

    2017-03-14

    Xp11 translocation renal cell carcinoma (RCC) are defined by chromosome translocations involving the Xp11 breakpoint which results in one of a variety of TFE3 gene fusions. TFE3 break-apart florescence in situ hybridization (FISH) assays are generally preferred to TFE3 immunohistochemistry (IHC) as a means of confirming the diagnosis in archival material, as FISH is less sensitive to the variable fixation which can result in false positive or false negative IHC. Prompted by a case report in the cytogenetics literature, we identify 3 cases of Xp11 translocation RCC characterized by a subtle chromosomal inversion involving the short arm of the X chromosome, resulting in an RBM10-TFE3 gene fusion. TFE3 rearrangement was not detected by conventional TFE3 break-apart FISH, but was suggested by strong diffuse TFE3 immunoreactivity in a clean background. We then developed novel fosmid probes to detect the RBM10-TFE3 gene fusion in archival material. These cases validate RBM10-TFE3 as a recurrent gene fusion in Xp11 translocation RCC, illustrate a source of false-negative TFE3 break-apart FISH, and highlight the complementary role of TFE3 IHC and TFE3 FISH.

  11. Clinical Data as an Adjunct to Ultrasound Reduces the False-Negative Malignancy Rate in BI-RADS 3 Breast Lesions

    PubMed Central

    Ackermann, S.; Schoenenberger, C.-A.; Zanetti-Dällenbach, R.

    2016-01-01

    Purpose: Ultrasound (US) is a well-established diagnostic procedure for breast examination. We investigated the malignancy rate in solid breast lesions according to their BI-RADS classification with a particular focus on false-negative BI-RADS 3 lesions. We examined whether patient history and clinical findings could provide additional information that would help determine further diagnostic steps in breast lesions. Materials and Methods: We conducted a retrospective study by exploring US BI-RADS in 1469 breast lesions of 1201 patients who underwent minimally invasive breast biopsy (MIBB) from January 2002 to December 2011. Results: The overall sensitivity and specificity of BI-RADS classification was 97.4% and 66.4%, respectively, with a positive (PPV) and negative predictive value (NPV) of 65% and 98%, respectively. In 506 BI-RADS 3 lesions, histology revealed 15 malignancies (2.4% malignancy rate), which corresponds to a false-negative rate (FNR) of 2.6%. Clinical evaluation and patient requests critically influenced the further diagnostic procedure, thereby prevailing over the recommendation given by the BI-RADS 3 classification. Conclusion: Clinical criteria including age, family and personal history, clinical examination, mammography and patient choice ensure adequate diagnostic procedures such as short-term follow-up or MIBB in patients with lesions classified as US-BI-RADS 3. PMID:27689181

  12. Low soil moisture during hot periods drives apparent negative temperature sensitivity of soil respiration in a dryland ecosystem: A multi-model comparison

    USGS Publications Warehouse

    Tucker, Colin; Reed, Sasha C.

    2016-01-01

    Arid and semiarid ecosystems (drylands) may dominate the trajectory of biosphere-to-atmosphere carbon (C) flux over the coming century. Accordingly, understanding dryland CO2 efflux controls is important for understanding C cycling at the global-scale: key unknowns regarding how temperature and moisture interact to regulate dryland C cycling remain. Further, the patchiness of dryland vegetation can create ‘islands of fertility’, with spatially heterogeneous rates of soil respiration (Rs). At our study site in southeastern Utah, USA we added or removed litter (0 to 650% of control) in paired plots that were either associated with a shrub or with interspaces between vascular plants. We measured Rs, soil temperature, and water content (θ) on eight sampling dates between October 2013 and November 2014. Rs was highest following monsoon rains in late summer when soil temperature was ~30°C. During mid-summer, Rs was low, associated with high soil temperatures (>40°C), resulting in an apparent negative temperature sensitivity of Rs at high temperatures, and positive temperature sensitivity at low-moderate temperatures. We used Bayesian statistical methods to compare multiple competing models capturing a wide range of hypothesized relationships between temperature, moisture, and Rs. The best fit model indicates apparent negative temperature sensitivity of soil respiration at high temperatures reflects the control of soil moisture – not high temperatures – in limiting Rs. The modeled Q10 ranged from 2.7 at 5°C to 1.4 at 45°C. Litter addition had no effect on temperature sensitivity or reference respiration (Rref = Rs at 20°C and optimum moisture) beneath shrubs, and little effect on Rref in interspaces, yet Rref was 1.5 times higher beneath shrubs than in interspaces. Together, these results suggest reduced Rs often observed at high temperatures in drylands is dominated by the control of moisture, and that variable litter inputs – at least over the short

  13. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    PubMed

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  14. Preventing intense false positive and negative reactions attributed to the principle of ELISA to re-investigate antibody studies in autoimmune diseases.

    PubMed

    Terato, Kuniaki; Do, Christopher T; Cutler, Dawn; Waritani, Takaki; Shionoya, Hiroshi

    2014-05-01

    To study the possible involvement of potential environmental pathogens in the pathogenesis of autoimmune diseases, it is essential to investigate antibody responses to a variety of environmental agents and autologous components. However, none of the conventional ELISA buffers can prevent the false positive and negative reactions attributed to its principal, which utilizes the high binding affinity of proteins to plastic surfaces. The aims of this study are to reveal all types of non-specific reactions associated with conventional buffer systems, and to re-investigate antibody responses to potential environmental pathogenic and autologous antigens in patients with autoimmune diseases using a newly developed buffer system "ChonBlock™" by ELISA. Compared to conventional buffers, the new buffer was highly effective in reducing the most intense false positive reaction caused by hydrophobic binding of immunoglobulin in sample specimens to plastic surfaces, "background (BG) noise reaction", and other non-specific reactions without interfering with antigen-antibody reactions. Applying this buffer, we found that IgG antibody responses to Escherichia coli O111:B4, E. coli lipopolysaccharide (LPS) and peptidoglycan polysaccharide (PG-PS) were significantly lower or tended to be lower in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), whereas IgA antibody responses to these antigens were equal or tended to be higher compared to normal controls. As a consequence, the IgA/IgG antibody ratios against these agents were significantly higher in patients with RA and SLE, except for Crohn's disease, which showed significantly higher IgG responses to these antigens. To assay antibodies in human sera, it is indispensable to eliminate false positive and negative reactions by using an appropriate buffer system, and to include antigen non-coated blank wells to determine BG noise reactions of invidual samples. Finally, based on our preliminary analysis in

  15. A low false negative filter for detecting rare bird species from short video segments using a probable observation data set-based EKF method.

    PubMed

    Song, Dezhen; Xu, Yiliang

    2010-09-01

    We report a new filter to assist the search for rare bird species. Since a rare bird only appears in front of a camera with very low occurrence (e.g., less than ten times per year) for very short duration (e.g., less than a fraction of a second), our algorithm must have a very low false negative rate. We verify the bird body axis information with the known bird flying dynamics from the short video segment. Since a regular extended Kalman filter (EKF) cannot converge due to high measurement error and limited data, we develop a novel probable observation data set (PODS)-based EKF method. The new PODS-EKF searches the measurement error range for all probable observation data that ensures the convergence of the corresponding EKF in short time frame. The algorithm has been extensively tested using both simulated inputs and real video data of four representative bird species. In the physical experiments, our algorithm has been tested on rock pigeons and red-tailed hawks with 119 motion sequences. The area under the ROC curve is 95.0%. During the one-year search of ivory-billed woodpeckers, the system reduces the raw video data of 29.41 TB to only 146.7 MB (reduction rate 99.9995%).

  16. False Negative Rates of a Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates via Real-Time PCR

    SciTech Connect

    Hutchison, Janine R.; Piepel, Gregory F.; Amidan, Brett G.; Sydor, Michael A.; Kaiser, Brooke L.D.

    2016-06-01

    Surface sampling for Bacillus anthracis spores has traditionally relied on detection via bacterial cultivation methods. Although effective, this approach does not provide the level of organism specificity that can be gained through molecular techniques. False negative rates (FNR) and limits of detection (LOD) were determined for two B. anthracis surrogates with modified rapid viability-polymerase chain reaction (mRV-PCR) following macrofoam-swab sampling. This study was conducted in parallel with a previously reported study that analyzed spores using a plate-culture method. B. anthracis Sterne (BAS) or B. atrophaeus Nakamura (BG) spores were deposited onto four surface materials (glass, stainless steel, vinyl tile, and plastic) at nine target concentrations (2 to 500 spores/coupon; 0.078 to 19.375 colony-forming units [CFU] per cm2). Mean FNR values for mRV-PCR analysis ranged from 0 to 0.917 for BAS and 0 to 0.875 for BG and increased as spore concentration decreased (over the concentrations investigated) for each surface material. FNRs based on mRV-PCR data were not statistically different for BAS and BG, but were significantly lower for glass than for vinyl tile. FNRs also tended to be lower for the mRV-PCR method compared to the culture method. The mRV-PCR LOD95 was lowest for glass (0.429 CFU/cm2 with BAS and 0.341 CFU/cm2 with BG) and highest for vinyl tile (0.919 CFU/cm2 with BAS and 0.917 CFU/cm2 with BG). These mRV-PCR LOD95 values were lower than the culture values (BAS: 0.678 to 1.023 CFU/cm2 and BG: 0.820 to 1.489 CFU/cm2). The FNR and LOD95 values reported in this work provide guidance for environmental sampling of Bacillus spores at low concentrations.

  17. Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

    SciTech Connect

    Piepel, Gregory F.; Hutchison, Janine R.; Deatherage Kaiser, Brooke L; Amidan, Brett G.; Sydor, Michael A.; Barrett, Christopher A.

    2015-03-31

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in. × 2 in.) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent report.

  18. Angina Relief by Ranolazine Identifies False-Negative SPECT Myocardial Perfusion Scans in Patients with Coronary Disease Demonstrated by Coronary Angiography

    PubMed Central

    Murray, Gary L.

    2014-01-01

    Normal myocardial perfusion imaging (MPI) reduces intermediate- or high-risk pretest probability patients to low- or intermediate-risk posttest probability, respectively, for coronary disease (CD). Since ranolazine (RAN) relieves only angina, anginal patients with normal MPI whose angina is relieved by RAN present a significant dilemma. The purpose of this retrospective chart review was to confirm the impression that coronary angiography (CA) is indicated in patients whose class 3 to 4 angina is relieved by RAN, but have normal myocardial single-photon emission computed tomography (SPECT) MPIs. Charts of patients with stable class 3 to 4 angina (typical and atypical) and normal MPIs (left ventricular ejection fraction [LVEF] ≥50% and segmental score = 0) were reviewed. CA was done on all the patients with complete angina relief taking RAN, as well as nonresponders whose anginal etiology could not be explained. Stenoses were considered flow-restrictive when more than 70% diameter stenosis is observed by quantitative CA, or, when 50 to 70%, fractional flow reserve (FFR) measured ≤0.80. RAN relieved angina in 36 of 54 (67%) patients. Of the known cases, 25 of these 36 (69%) had 43 stenoses ≥50% (mean = 66%): 15 (60%) had 1 vessel disease; 9 (36%) had multivessel disease; 18 (72%) had left anterior descending (LAD) disease; 1 (4%) had left main disease. Twenty one of 43 (49%) stenosis were > 70%; 22 (51%) stenoses were 50 to 70% and required FFR measurement. Twenty nine of 43 stenoses (67%) were considered flow-restrictive in 18 of these 25 (72%) patients. Eight RAN nonresponders with no explanation for angina had no CD at CA. RAN angina relief is invaluable in identifying falsely negative SPECT MPI, and 50% of these patients have flow-restrictive stenoses. PMID:25317027

  19. Diagnostic utility of small-caliber and conventional endoscopes for gastric cancer and analysis of endoscopic false-negative gastric cancers

    PubMed Central

    Kataoka, Hiromi; Mizuno, Kiyoshi; Hayashi, Noriyuki; Tanaka, Mamoru; Nishiwaki, Hirotaka; Ebi, Masahide; Mizoshita, Tsutomu; Mori, Yoshinori; Kubota, Eiji; Tanida, Satoshi; Kamiya, Takeshi; Joh, Takashi

    2013-01-01

    AIM: To analyze the diagnostic utility of a small-caliber endoscope (SC-E) and clinicopathological features of false-negative gastric cancers (FN-GCs). METHODS: A total of 21638 esophagogastroduodenoscopy (EGD) gastric cancer (GC) screening examinations were analyzed. Secondary endoscopic examinations (n = 3352) were excluded because most secondary examinations tended to be included in the conventional endoscopy (C-E) group. Detection rates of GCs and FN-GCs were compared between SC-E and C-E groups. FN-GC was defined as GC performed with EGD within the past 3 years without GC detection. Macroscopic types, histopathological characteristics and locations of FN-GCs were compared with firstly found-gastric cancers (FF-GCs) in detail. RESULTS: SC-E cases (n = 6657) and C-E cases (n = 11644), a total of 18301 cases, were analyzed. GCs were detected in 16 (0.24%) SC-E cases and 40 C-E (0.34%) cases (P = 0.23) and there were 4 FN-GCs (0.06%) in SC-E and 13 (0.11%) in C-E (P = 0.27), with no significant difference. FN-GCs/GCs ratio between SC-E and C-E groups was not significantly different (P = 0.75). The comparison of endoscopic macroscopic types of FN-GCs tended to be a less advanced type (P = 0.02). Histopathologically, 70.6% of FN-GCs were differentiated and 29.4% undifferentiated type. On the other hand, 43.0% of FF-GCs were differentiated and 53.8% undifferentiated type, so FN-GCs tended to be more differentiated type (P = 0.048). CONCLUSION: The diagnostic utility of SC-E for the detection of GCs and FN-GCs was not inferior to that of C-E. Careful observation for superficially depressed type lesions in the upper lesser curvature region is needed to decrease FN-GCs. PMID:24044043

  20. False Negative Rates of a Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates via Real-Time PCR

    SciTech Connect

    Hutchison, Janine R.; Piepel, Gregory F.; Amidan, Brett G.; Sydor, Michael A.; Deatherage Kaiser, Brooke L

    2015-05-01

    Surface sampling for Bacillus anthracis spores has traditionally relied on detection via bacterial cultivation methods. Although effective, this approach does not provide the level of organism specificity that can be gained through molecular techniques. False negative rates (FNR) and limits of detection (LOD) were determined for two B. anthracis surrogates with modified rapid viability-polymerase chain reaction (mRV-PCR) following macrofoam-swab sampling. This study was conducted in parallel with a previously reported study that analyzed spores using a plate-culture method. B. anthracis Sterne (BAS) or B. atrophaeus Nakamura (BG) spores were deposited onto four surface materials (glass, stainless steel, vinyl tile, and plastic) at nine target concentrations (2 to 500 spores/coupon; 0.078 to 19.375 colony-forming units [CFU] per cm²). Mean FNR values for mRV-PCR analysis ranged from 0 to 0.917 for BAS and 0 to 0.875 for BG and increased as spore concentration decreased (over the concentrations investigated) for each surface material. FNRs based on mRV-PCR data were not statistically different for BAS and BG, but were significantly lower for glass than for vinyl tile. FNRs also tended to be lower for the mRV-PCR method compared to the culture method. The mRV-PCR LOD₉₅ was lowest for glass (0.429 CFU/cm² with BAS and 0.341 CFU/cm² with BG) and highest for vinyl tile (0.919 CFU/cm² with BAS and 0.917 CFU/cm² with BG). These mRV-PCR LOD₉₅ values were lower than the culture values (BAS: 0.678 to 1.023 CFU/cm² and BG: 0.820 to 1.489 CFU/cm²). The FNR and LOD₉₅ values reported in this work provide guidance for environmental sampling of Bacillus spores at low concentrations.

  1. Modified transition state theory and negative apparent activation energies of simple metathesis reactions: application to the reaction CH3 + HBr --> CH4 + Br.

    PubMed

    Krasnoperov, Lev N; Peng, Jingping; Marshall, Paul

    2006-03-09

    A modified transition state theory (MTST) has been developed for gas-phase reactions with "negative barriers". The theory was applied to the reactions CH3 + HBr(DBr) --> CH4(CH3D) + Br (1a, 1b), which exhibit negative temperature dependences. Accurate ab initio calculations performed with coupled cluster theory extrapolated to the complete basis set limit revealed a transition state located at -2.3 kJ mol(-1) relative to the ground state of the reactants (in reaction 1a), as well as a shallow bound complex. The negative temperature dependence, the absolute values of the rate constant, and the isotope substitution effect are reproduced with good accuracy (10%), without any adjustment or fitting parameters. Analytical expressions are presented for MTST including angular momentum conservation, centrifugal barriers and tunneling. This analysis uses information about the possibly loose entrance barrier and the transition state but does not invoke a statistical intermediate complex.

  2. False Memories for Affective Information in Schizophrenia

    PubMed Central

    Fairfield, Beth; Altamura, Mario; Padalino, Flavia A.; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola

    2016-01-01

    Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p < 0.05) when remembering episodes with positive or negative outcomes. The effect of valence was apparent in the patient group. For example, it did not affect the production causal false memories (p > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved. PMID:27965600

  3. False Memories for Affective Information in Schizophrenia.

    PubMed

    Fairfield, Beth; Altamura, Mario; Padalino, Flavia A; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola

    2016-01-01

    Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p < 0.05) when remembering episodes with positive or negative outcomes. The effect of valence was apparent in the patient group. For example, it did not affect the production causal false memories (p > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved.

  4. False assumptions.

    PubMed

    Swaminathan, M

    1997-01-01

    Indian women do not have to be told the benefits of breast feeding or "rescued from the clutches of wicked multinational companies" by international agencies. There is no proof that breast feeding has declined in India; in fact, a 1987 survey revealed that 98% of Indian women breast feed. Efforts to promote breast feeding among the middle classes rely on such initiatives as the "baby friendly" hospital where breast feeding is promoted immediately after birth. This ignores the 76% of Indian women who give birth at home. Blaming this unproved decline in breast feeding on multinational companies distracts attention from more far-reaching and intractable effects of social change. While the Infant Milk Substitutes Act is helpful, it also deflects attention from more pressing issues. Another false assumption is that Indian women are abandoning breast feeding to comply with the demands of employment, but research indicates that most women give up employment for breast feeding, despite the economic cost to their families. Women also seek work in the informal sector to secure the flexibility to meet their child care responsibilities. Instead of being concerned about "teaching" women what they already know about the benefits of breast feeding, efforts should be made to remove the constraints women face as a result of their multiple roles and to empower them with the support of families, governmental policies and legislation, employers, health professionals, and the media.

  5. False-negative contrast-enhanced spectral mammography: use of more than one imaging modality and application of the triple test avoids misdiagnosis.

    PubMed

    Taylor, Donna; O'Hanlon, Susan; Latham, Bruce

    2017-03-31

    A 50-year-old woman presented with chest tenderness. On examination, both breasts were lumpy. Bilateral mammography showed heterogeneously dense parenchyma, with possible stromal distortion laterally on the right at the 0900 position. On ultrasound (US), a corresponding 13×9×10 mm irregular hypoechoic mass with internal vascularity was noted and both breasts had a complex heterogeneous fibroglandular background pattern. US-guided core biopsy with marker clip insertion was performed with the diagnosis of a grade 2 invasive ductal carcinoma (IDC). In view of the parenchymal pattern on mammography and US, contrast-enhanced spectral mammography (CESM) was performed for local staging. Mild background enhancement was noted, but there was no enhancement at the lesion site. The patient elected to have bilateral mastectomies and sentinel node biopsies. Final histopathology showed a node negative 11 mm grade 2 oestrogen and progesterone receptor positive, IDC.

  6. Development of a Taqman RT-PCR assay for the detection and quantification of negatively stranded RNA of human enteroviruses: evidence for false-priming and improvement by tagged RT-PCR.

    PubMed

    Bessaud, Maël; Autret, Arnaud; Jegouic, Sophie; Balanant, Jean; Joffret, Marie-Line; Delpeyroux, Francis

    2008-11-01

    Human enteroviruses are among the most common viruses infecting humans. These viruses are known to be able to infect a wide range of tissues and are believed to establish persistent infections. Enteroviruses are positive-sense single-stranded RNA viruses whose replication involves the synthesis of negative strand intermediates. Therefore, the specific detection of negatively stranded viral RNA in tissues or cells is a reliable marker of active enteroviral replication. The present report presents the development of a real-time RT-PCR allowing the specific detection and quantification of negatively stranded viral RNA. Since it was known that specific amplification of single-stranded RNA can be made difficult by false-priming events leading to false-positive or overestimated results, the assay was developed by using a tagged RT primer. This tagged RT-PCR was shown to be able to amplify specifically negative RNA of enteroviruses grown in cell cultures by preventing the amplification of cDNAs generated by false-priming.

  7. Positive consequences of false memories.

    PubMed

    Howe, Mark L; Garner, Sarah R; Patel, Megan

    2013-01-01

    Previous research is replete with examples of the negative consequences of false memories. In the current research, we provide a different perspective on false memories and their development and demonstrate that false memories can have positive consequences. Specifically, we examined the role false memories play in subsequent problem-solving tasks. Children and adults studied and recalled neutral or survival-relevant lists of associated words. They then solved age-normed compound remote associates, some of whose solutions had been primed by false memories created when studying the previous lists. The results showed that regardless of age: (a) survival-related words were not only better recollected but were also more susceptible than neutral words to false memory illusions; and (b) survival-related false memories were better than neutral false memories as primes for problem-solving. These findings are discussed in the context of recent speculation concerning the positive consequences of false memories, and the adaptive nature of reconstructive memory.

  8. Quantitative real-time PCR as a sensitive protein-protein interaction quantification method and a partial solution for non-accessible autoactivator and false-negative molecule analysis in the yeast two-hybrid system.

    PubMed

    Maier, Richard H; Maier, Christina J; Hintner, Helmut; Bauer, Johann W; Onder, Kamil

    2012-12-01

    Many functional proteomic experiments make use of high-throughput technologies such as mass spectrometry combined with two-dimensional polyacrylamide gel electrophoresis and the yeast two-hybrid (Y2H) system. Currently there are even automated versions of the Y2H system available that can be used for proteome-wide research. The Y2H system has the capacity to deliver a profusion of Y2H positive colonies from a single library screen. However, subsequent analysis of these numerous primary candidates with complementary methods can be overwhelming. Therefore, a method to select the most promising candidates with strong interaction properties might be useful to reduce the number of candidates requiring further analysis. The method described here offers a new way of quantifying and rating the performance of positive Y2H candidates. The novelty lies in the detection and measurement of mRNA expression instead of proteins or conventional Y2H genetic reporters. This method correlates well with the direct genetic reporter readouts usually used in the Y2H system, and has greater sensitivity for detecting and quantifying protein-protein interactions (PPIs) than the conventional Y2H system, as demonstrated by detection of the Y2H false-negative PPI of RXR/PPARG. Approximately 20% of all proteins are not suitable for the Y2H system, the so-called autoactivators. A further advantage of this method is the possibility to evaluate molecules that usually cannot be analyzed in the Y2H system, exemplified by a VDR-LXXLL motif peptide interaction.

  9. False-negative rate, limit of detection and recovery efficiency performance of a validated macrofoam-swab sampling method for low surface concentrations of Bacillus anthracis Sterne and Bacillus atrophaeus spores

    SciTech Connect

    Piepel, G. F.; Deatherage Kaiser, B. L.; Amidan, B. G.; Sydor, M. A.; Barrett, C. A.; Hutchison, J. R.

    2016-05-06

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in × 2 in) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS and 40.2% with BG) and the highest for glass (92.8% with BAS and 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG; values increased as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent article.

  10. MSPI False Indication Probability Simulations

    SciTech Connect

    Dana Kelly; Kurt Vedros; Robert Youngblood

    2011-03-01

    This paper examines false indication probabilities in the context of the Mitigating System Performance Index (MSPI), in order to investigate the pros and cons of different approaches to resolving two coupled issues: (1) sensitivity to the prior distribution used in calculating the Bayesian-corrected unreliability contribution to the MSPI, and (2) whether (in a particular plant configuration) to model the fuel oil transfer pump (FOTP) as a separate component, or integrally to its emergency diesel generator (EDG). False indication probabilities were calculated for the following situations: (1) all component reliability parameters at their baseline values, so that the true indication is green, meaning that an indication of white or above would be false positive; (2) one or more components degraded to the extent that the true indication would be (mid) white, and “false” would be green (negative) or yellow (negative) or red (negative). In key respects, this was the approach taken in NUREG-1753. The prior distributions examined were the constrained noninformative (CNI) prior used currently by the MSPI, a mixture of conjugate priors, the Jeffreys noninformative prior, a nonconjugate log(istic)-normal prior, and the minimally informative prior investigated in (Kelly et al., 2010). The mid-white performance state was set at ?CDF = ?10 ? 10-6/yr. For each simulated time history, a check is made of whether the calculated ?CDF is above or below 10-6/yr. If the parameters were at their baseline values, and ?CDF > 10-6/yr, this is counted as a false positive. Conversely, if one or all of the parameters are set to values corresponding to ?CDF > 10-6/yr but that time history’s ?CDF < 10-6/yr, this is counted as a false negative indication. The false indication (positive or negative) probability is then estimated as the number of false positive or negative counts divided by the number of time histories (100,000). Results are presented for a set of base case parameter values

  11. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

    2011-05-01

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the false negative rate (FNR). The FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not FNR (which left a major gap in available information). Quantifying the FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The testing was performed by SNL and is now completed. The study investigated the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge

  12. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

    2010-12-16

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 - PCD). The PCD/FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not PCD/FNR (which left a major gap in available information). Quantifying the PCD/FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in PCD/FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The study will investigate the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination

  13. False color viewing device

    DOEpatents

    Kronberg, J.W.

    1992-10-20

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs.

  14. False color viewing device

    DOEpatents

    Kronberg, James W.

    1992-01-01

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  15. False color viewing device

    DOEpatents

    Kronberg, J.W.

    1991-05-08

    This invention consists of a viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching, the user`s eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  16. False Color Bands

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    In a gray scale image, the suble variations seen in this false color image are almost impossible to identify. Note the orange band in the center of the frame, and the bluer bands to either side of it.

    Image information: VIS instrument. Latitude 87, Longitude 65.5 East (294.5 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. An effective method for controlling false discovery and false nondiscovery rates in genome-scale RNAi screens.

    PubMed

    Zhang, Xiaohua Douglas

    2010-10-01

    In most genome-scale RNA interference (RNAi) screens, the ultimate goal is to select siRNAs with a large inhibition or activation effect. The selection of hits typically requires statistical control of 2 errors: false positives and false negatives. Traditional methods of controlling false positives and false negatives do not take into account the important feature in RNAi screens: many small-interfering RNAs (siRNAs) may have very small but real nonzero average effects on the measured response and thus cannot allow us to effectively control false positives and false negatives. To address for deficiencies in the application of traditional approaches in RNAi screening, the author proposes a new method for controlling false positives and false negatives in RNAi high-throughput screens. The false negatives are statistically controlled through a false-negative rate (FNR) or false nondiscovery rate (FNDR). FNR is the proportion of false negatives among all siRNAs examined, whereas FNDR is the proportion of false negatives among declared nonhits. The author also proposes new concepts, q*-value and p*-value, to control FNR and FNDR, respectively. The proposed method should have broad utility for hit selection in which one needs to control both false discovery and false nondiscovery rates in genome-scale RNAi screens in a robust manner.

  18. Moon - False Color Mosaic

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This false-color mosaic was constructed from a series of 53 images taken through three spectral filters by Galileo's imaging system as the spacecraft flew over the northern regions of the Moon on December 7, 1992. The part of the Moon visible from Earth is on the left side in this view. The color mosaic shows compositional variations in parts of the Moon's northern hemisphere. Bright pinkish areas are highlands materials, such as those surrounding the oval lava-filled Crisium impact basin toward the bottom of the picture. Blue to orange shades indicate volcanic lava flows. To the left of Crisium, the dark blue Mare Tranquillitatis is richer in titanium than the green and orange maria above it. Thin mineral-rich soils associated with relatively recent impacts are represented by light blue colors; the youngest craters have prominent blue rays extending from them. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.

  19. North Polar False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This full resolution image contains dunes, and small areas of 'blue' which may represent fresh (ie. not dust covered) frost or ice.

    Image information: VIS instrument. Latitude 85, Longitude 235.8 East (124.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. False Color Aurora

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Data from NASA's Galileo spacecraft were used to produce this false-color composite of Jupiter's northern aurora on the night side of the planet. The height of the aurora, the thickness of the auroral arc, and the small-scale structure are revealed for the first time. Images in Galileo's red, green, and clear filters are displayed in red, green, and blue respectively. The smallest resolved features are tens of kilometers in size, which is a ten-fold improvement over Hubble Space Telescope images and a hundred-fold improvement over ground-based images.

    The glow is caused by electrically charged particles impinging on the atmosphere from above. The particles travel along Jupiter's magnetic field lines, which are nearly vertical at this latitude. The auroral arc marks the boundary between the 'closed' field lines that are attached to the planet at both ends and the 'open' field lines that extend out into interplanetary space. At the boundary the particles have been accelerated over the greatest distances, and the glow is especially intense.

    The latitude-longitude lines refer to altitudes where the pressure is 1 bar. The image shows that the auroral emissions originate about 500 kilometers (about 310 miles) above this surface. The colored background is light scattered from Jupiter's bright crescent, which is out of view to the right. North is at the top. The images are centered at 57 degrees north and 184 degrees west and were taken on April 2, 1997 at a range of 1.7 million kilometers (1.05 million miles) by Galileo's Solid State Imaging (SSI) system.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at: http:// galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.

  1. A Study of False-Positive and False-Negative Error Rates in Cartridge Case Comparisons

    DTIC Science & Technology

    2014-04-07

    Defense Biometrics and Forensics Office, Assistant Secretary of Defense (Research and Engineering), through the U.S. Department of Energy Contract No...official policies, either expressed or implied, of the Defense Biometrics and Forensics Office, Defense Forensic Science Center, or the U.S...Acknowledgements This work was supported by Defense Biometrics and Forensics Office through the U.S. Department of Energy under Contract No. DE-AC02

  2. Identification and classification of skin sensitizers: identifying false positives and false negatives.

    PubMed

    Basketter, David A; McFadden, John; Evans, Peter; Andersen, Klaus E; Jowsey, Ian

    2006-11-01

    The first step in regulatory evaluation of substances involves the identification of their intrinsic hazards, including the potential for skin sensitization. This is, quite properly, entirely different from assessment of the risks to human health, which might arise from incorporation of substances in products. EU guidance on regulations concerning the classification of skin sensitizers suggests a range of sources of information be deployed in the hazard identification process. These include chemical structure, predictive animal tests, and various types of human data. Where the information is clear-cut, then uncertainties rarely arise. However, for some materials, discordant information arises, perhaps because the substance is on the borderline of test sensitivity and classification (sensitizing materials of insufficient potency do not classified according to the EU scheme), due to conflicting results in predictive tests or for other reasons. In this study, we review data on a number of substances where a classification decision is complicated by such discordances and seek to use these examples to demonstrate how best to make a weight of evidence decision on whether a substance should, or should not, be classified as a skin sensitizer.

  3. Sporadic bilateral adrenal medullary hyperplasia: apparent false positive MIBG scan and expected MRI findings.

    PubMed

    Yung, B C; Loke, T K; Tse, T W; Tsang, M W; Chan, J C

    2000-10-01

    Adrenal medullary hyperplasia is a rare cause of clinical symptoms and biochemical findings identical to pheochromocytoma occurring mostly in multiple endocrine neoplasia patients. The scenario of positive MIBG scan, but no focal lesion found on CT and MRI led to diagnostic and management difficulties. Like pheochromocytoma, surgical excision can lead to clinical and biochemical recovery. We report this unusual case of sporadic bilateral adrenal medullary hyperplasia, with hypertension and biochemical abnormalities alleviated after surgical adrenalectomy. Based on T2 values reported in literature, high signal focal lesions may not appear on T2-weighted MRI images until development of frank pheochromocytoma. MIBG scan remains the most sensitive imaging modality for this condition.

  4. False-Negative Interpretations in a CAD Environment

    DTIC Science & Technology

    2001-08-01

    Radiol 1997; 4:497-502. 14. Mendez AJ, Tahocas PG, Loda MJ. Computer-aided diagnosis: auto- 25. Zheng B, Chang Y-H, Wang X-H, Good WF. Applying a genetic...Ph.D. Marie A. Ganott, M.D. Cynthia A. Britton, M.D. Christiane M. Hakim, M.D. Lara A. Hardesty, M.D. Thomas S. Chang, M.D. Howard E. Rockette, Ph.D

  5. Dynamics of false vacuum bubbles with nonminimal coupling

    SciTech Connect

    Lee, Bum-Hoon; Lee, Chul H.; Lee, Wonwoo; Nam, Siyoung; Park, Chanyong

    2008-03-15

    We study the dynamics of false vacuum bubbles. A nonminimally coupled scalar field gives rise to the effect of negative tension. The mass of a false vacuum bubble from an outside observer's point of view can be positive, zero, or negative. The interior false vacuum has de Sitter geometry, while the exterior true vacuum background can have geometry depending on the vacuum energy. We show that there exist expanding false vacuum bubbles without the initial singularity in the past.

  6. White Rock in False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    This false color image shows the wind eroded deposit in Pollack Crater called 'White Rock'. This image was collected during the Southern Fall Season.

    Image information: VIS instrument. Latitude -8, Longitude 25.2 East (334.8 West). 0 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of

  7. Iani Chaos in False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    This false color image of a portion of the Iani Chaos region was collected during the Southern Fall season.

    Image information: VIS instrument. Latitude -2.6 Longitude 342.4 East (17.6 West). 36 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The

  8. False Position, Double False Position and Cramer's Rule

    ERIC Educational Resources Information Center

    Boman, Eugene

    2009-01-01

    We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.

  9. Maltreatment increases spontaneous false memories but decreases suggestion-induced false memories in children.

    PubMed

    Otgaar, Henry; Howe, Mark L; Muris, Peter

    2017-01-17

    We examined the creation of spontaneous and suggestion-induced false memories in maltreated and non-maltreated children. Maltreated and non-maltreated children were involved in a Deese-Roediger-McDermott false memory paradigm where they studied and remembered negative and neutral word lists. Suggestion-induced false memories were created using a misinformation procedure during which both maltreated and non-maltreated children viewed a negative video (i.e., bank robbery) and later received suggestive misinformation concerning the event. Our results showed that maltreated children had higher levels of spontaneous negative false memories but lower levels of suggestion-induced false memories as compared to non-maltreated children. Collectively, our study demonstrates that maltreatment both increases and decreases susceptibility to memory illusions depending on the type of false memory being induced. Statement of contribution What is already known on this subject? Trauma affects memory. It is unclear how trauma affects false memory. What does this study add? This study focuses on two types of false memories.

  10. False memories for aggressive acts.

    PubMed

    Laney, Cara; Takarangi, Melanie K T

    2013-06-01

    Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed.

  11. Penrose inequality and apparent horizons

    SciTech Connect

    Ben-Dov, Ishai

    2004-12-15

    A spherically symmetric spacetime is presented with an initial data set that is asymptotically flat, satisfies the dominant energy condition, and such that on this initial data M<{radical}(A/16{pi}), where M is the total mass and A is the area of the apparent horizon. This provides a counterexample to a commonly stated version of the Penrose inequality, though it does not contradict the true Penrose inequality.

  12. The Kepler False Positive Table

    NASA Astrophysics Data System (ADS)

    Bryson, Steve; Kepler False Positive Working Group

    2015-01-01

    The Kepler Space Telescope has detected thousands of candidate exoplanets by observing transit signals in a sample of more than 190,000 stars. Many of these transit signals are false positives, defined as a transit-like signal that is not due to a planet orbiting the target star (or a bound companion if the target is a multiple-star system). Astrophysical causes of false positives include background eclipsing binaries, planetary transits not associated with the target star, and non-planetary eclipses of the target star by stellar companions. The fraction of Kepler planet candidates that are false positives ranges from about 10% at high Galactic latitudes to 40% at low Galactic latitudes. Creating a high-reliability planet candidate catalog for statistical studies such as occurrence rate calculations requires removing clearly identified false positives.The Kepler Object of Interest (KOI) catalog at the NExScI NASA Exoplanet Archive flags false positives, and will soon provide a high-level classification of false positives, but lacks detailed description of why a KOI was determined to be a false positive. The Kepler False Positive Working Group (FPWG) examines each false positive in detail to certify that it is correctly identified as a false positive, and determines the primary reason(s) a KOI is classified as a false positive. The work of the FPWG will be published as the Kepler False Positive Table, hosted at the NExScI NASA Exoplanet Archive.The Kepler False Positive Table provides detailed information on the evidence for background binaries, transits caused by stellar companions, and false alarms. In addition to providing insight into the Kepler false positive population, the false positive table gives information about the background binary population and other areas of astrophysical interest. Because a planet around a star not associated with the target star is considered a false positive, the false positive table likely contains further planet candidates

  13. Sleep deprivation and false memories.

    PubMed

    Frenda, Steven J; Patihis, Lawrence; Loftus, Elizabeth F; Lewis, Holly C; Fenn, Kimberly M

    2014-09-01

    Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.

  14. False Belief vs. False Photographs: A Test of Theory of Mind or Working Memory?

    PubMed

    Callejas, Alicia; Shulman, Gordon L; Corbetta, Maurizio

    2011-01-01

    Theory of mind (ToM), the ability to reason about other people's thoughts and beliefs, has been traditionally studied in behavioral and neuroimaging experiments by comparing performance in "false belief" and "false photograph" (control) stories. However, some evidence suggests that these stories are not matched in difficulty, complicating the interpretation of results. Here, we more fully evaluated the relative difficulty of comprehending these stories and drawing inferences from them. Subjects read false belief and false photograph stories followed by comprehension questions that probed true ("reality" questions) or false beliefs ("representation" questions) appropriate to the stories. Stories and comprehension questions were read and answered, respectively, more slowly in the false photograph than false belief conditions, indicating their greater difficulty. Interestingly, accuracy on representation questions for false photograph stories was significantly lower than for all other conditions and correlated positively with participants' working memory span scores. These results suggest that drawing representational inferences from false photo stories is particularly difficult and places heavy demands on working memory. Extensive naturalistic practice with ToM reasoning may enable a more flexible and efficient mental representation of false belief stories, resulting in lower memory load requirements. An important implication of these results is that the differential modulation of right temporal-parietal junction (RTPJ) during ToM and "false photo" control conditions may reflect the documented negative correlation of RTPJ activity with working memory load rather than a specialized involvement in ToM processes.

  15. Memory distrust syndrome, confabulation and false confession.

    PubMed

    Gudjonsson, Gisli

    2017-02-01

    There are three types of false confessions: 'voluntary', 'pressured-compliant' and 'pressured-internalized'. On the basis of case studies, in the early 1980s Gudjonsson and MacKeith coined the term 'memory distrust syndrome (MDS)' to describe a condition where people develop profound distrust of their memory and become susceptible to relying on external cues and suggestions from others. Memory distrust can, under certain circumstances, lead to a false confession, particularly of the pressured-internalized type, described as 'confabulation'. This article reviews the evidence for the condition and the psychological mechanism and processes involved. A heuristic model is then presented of a 32 year old man who falsely confessed to murder whilst in police custody. The key elements of the model involve the impact of 'contextual risk factors' (i.e., isolation, long and persistent guilt presumptive interrogation, and high emotional intensity) on 'enduring' vulnerability and 'acute state' factors. The detainee had kept a detailed diary whilst in solitary confinement that provided a unique insight into the gradual development of a MDS, his mental state, and thinking process. This type of false confession is apparently quite rare, but it can occur in intellectually able and educated individuals and involves 'delayed' rather than 'immediate' suggestibility.

  16. Multiple splicing defects in an intronic false exon.

    PubMed

    Sun, H; Chasin, L A

    2000-09-01

    Splice site consensus sequences alone are insufficient to dictate the recognition of real constitutive splice sites within the typically large transcripts of higher eukaryotes, and large numbers of pseudoexons flanked by pseudosplice sites with good matches to the consensus sequences can be easily designated. In an attempt to identify elements that prevent pseudoexon splicing, we have systematically altered known splicing signals, as well as immediately adjacent flanking sequences, of an arbitrarily chosen pseudoexon from intron 1 of the human hprt gene. The substitution of a 5' splice site that perfectly matches the 5' consensus combined with mutation to match the CAG/G sequence of the 3' consensus failed to get this model pseudoexon included as the central exon in a dhfr minigene context. Provision of a real 3' splice site and a consensus 5' splice site and removal of an upstream inhibitory sequence were necessary and sufficient to confer splicing on the pseudoexon. This activated context also supported the splicing of a second pseudoexon sequence containing no apparent enhancer. Thus, both the 5' splice site sequence and the polypyrimidine tract of the pseudoexon are defective despite their good agreement with the consensus. On the other hand, the pseudoexon body did not exert a negative influence on splicing. The introduction into the pseudoexon of a sequence selected for binding to ASF/SF2 or its replacement with beta-globin exon 2 only partially reversed the effect of the upstream negative element and the defective polypyrimidine tract. These results support the idea that exon-bridging enhancers are not a prerequisite for constitutive exon definition and suggest that intrinsically defective splice sites and negative elements play important roles in distinguishing the real splicing signal from the vast number of false splicing signals.

  17. Reduced False Memory after Sleep

    ERIC Educational Resources Information Center

    Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.

    2009-01-01

    Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False…

  18. Study modality and false recall.

    PubMed

    Smith, Rebekah E; Engle, Randall W

    2011-01-01

    False memories occur when individuals mistakenly report an event as having taken place when that event did not in fact occur. The DRM (Deese, 1959; Roediger & McDermott, 1995) paradigm provides an effective technique for creating and investigating false memories. In this paradigm participants study a list of words (e.g., SOUR, CANDY,…) that are highly associated to a non-presented critical item (e.g., SWEET). The study phase is followed by a test of memory for the study list words. Researchers typically find very high levels of false recall of the critical non-presented item. However, the likelihood of falsely remembering the non-presented critical items can be reduced by presenting studied associates visually rather than auditorally (e.g., Smith & Hunt, 1998). This is referred to as the modality effect in false memory. The current study investigated the role of resource availability in the expression of this modality effect in false recall. In Experiment 1 false recall was reduced in the visual study presentation condition relative to the auditory condition for participants with higher working memory capacity, but not for participants with lower working memory capacity. In Experiment 2 the effect of study modality on false recall was eliminated by the addition of a divided attention task at encoding. Both studies support the proposal that resource availability plays a role in the expression of the modality effect in the DRM paradigm (Smith, Lozito, & Bayen, 2005).

  19. The apparent diffusion coefficient does not reflect cytotoxic edema on the uninjured side after traumatic brain injury.

    PubMed

    Lu, Hong; Lei, Xiaoyan

    2014-05-01

    After traumatic brain injury, vasogenic and cytotoxic edema appear sequentially on the involved side. Neuroimaging investigations of edema on the injured side have employed apparent diffusion coefficient measurements in diffusion tensor imaging. We investigated the changes occurring on the injured and uninjured sides using diffusion tensor imaging/apparent diffusion coefficient and histological samples in rats. We found that, on the injured side, that vasogenic edema appeared at 1 hour and intracellular edema appeared at 3 hours. Mixed edema was observed at 6 hours, worsening until 12-24 hours post-injury. Simultaneously, microglial cells proliferated at the trauma site. Apparent diffusion coefficient values increased at 1 hour, decreased at 6 hours, and increased at 12 hours. The uninjured side showed no significant pathological change at 1 hour after injury. Cytotoxic edema appeared at 3 hours, and vasogenic edema was visible at 6 hours. Cytotoxic edema persisted, but vasogenic edema tended to decrease after 12-24 hours. Despite this complex edema pattern on the uninjured side with associated pathologic changes, no significant change in apparent diffusion coefficient values was detected over the first 24 hours. Apparent diffusion coefficient values accurately detected the changes on the injured side, but did not detect the changes on the uninjured side, giving a false-negative result.

  20. Tunneling decay of false kinks

    NASA Astrophysics Data System (ADS)

    Dupuis, Éric; Gobeil, Yan; MacKenzie, Richard; Marleau, Luc; Paranjape, M. B.; Ung, Yvan

    2015-07-01

    We consider the decay of "false kinks," that is, kinks formed in a scalar field theory with a pair of degenerate symmetry-breaking false vacua in 1 +1 dimensions. The true vacuum is symmetric. A second scalar field and a peculiar potential are added in order for the kink to be classically stable. We find an expression for the decay rate of a false kink. As with any tunneling event, the rate is proportional to exp (-SE) where SE is the Euclidean action of the bounce describing the tunneling event. This factor varies wildly depending on the parameters of the model. Of interest is the fact that for certain parameters SE can get arbitrarily small, implying that the kink is only barely stable. Thus, while the false vacuum itself may be very long-lived, the presence of kinks can give rise to rapid vacuum decay.

  1. False allegation of child abduction.

    PubMed

    Canning, Kathleen E; Hilts, Mark A; Muirhead, Yvonne E

    2011-05-01

    Cases in which a child has been falsely reported as missing or abducted can be extremely challenging to the law enforcement agencies responsible for their investigation. In the absence of a witnessed abduction or an obvious crime scene, it is difficult to determine whether a child has actually been abducted or has become a victim of a homicide and a false allegation. The purpose of this study was to examine falsely alleged kidnapping cases and identify successful investigative strategies. Sixty-one adjudicated false allegation cases involving 66 victims were analyzed. The mean age of the victim was 5 years. Victims came from generally unstable, high-risk family situations and were killed primarily by biological parents. Victims were killed because they were unwanted or viewed as an obstacle to a desired goal, or they were victims of abuse or maltreatment that ended in fatality.

  2. Ego depletion results in an increase in spontaneous false memories.

    PubMed

    Otgaar, Henry; Alberts, Hugo; Cuppens, Lesly

    2012-12-01

    The primary aim of the current study was to examine whether depleted cognitive resources might have ramifications for the formation of neutral and negative spontaneous false memories. To examine this, participants received neutral and negative Deese/Roediger-McDermott false memory wordlists. Also, for half of the participants, cognitive resources were depleted by use of an ego depletion manipulation (solving difficult calculations while being interfered with auditory noise). Our chief finding was that depleted cognitive resources made participants more vulnerable for the production of false memories. Our results shed light on how depleted cognitive resources affect neutral and negative correct and errant memories.

  3. Bubbling the false vacuum away

    SciTech Connect

    Gleiser, M.; Rogers, B.; Thorarinson, J.

    2008-01-15

    We investigate the role of nonperturbative, bubblelike inhomogeneities on the decay rate of false-vacuum states in two- and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum, as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubblelike inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay--known as resonant nucleation--is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and crossover. Possible applications are briefly discussed.

  4. Tunneling decay of false vortices

    NASA Astrophysics Data System (ADS)

    Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han

    2013-10-01

    We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.

  5. Sleep Loss Produces False Memories

    PubMed Central

    Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich

    2008-01-01

    People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., “night”, “dark”, “coal”,…), lacking the strongest common associate or theme word (here: “black”). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss. PMID:18946511

  6. The Danger of False Dichotomies.

    ERIC Educational Resources Information Center

    LaBoskey, Vicky Kubler

    1998-01-01

    Responds to an article that examined 10 dichotomies in teacher education (SP 527 128), suggesting that too much time and energy are spent debating false dichotomies and addressing two specific dichotomies (preservice versus inservice and campus versus school site). Recommends that professional educators pool their energy and collaborate (rather…

  7. Evolutionary Psychology and False Confession

    ERIC Educational Resources Information Center

    Bering, Jesse M.; Shackelford, Todd K.

    2005-01-01

    This paper presents comments on Kassin's review, (see record 2005-03019-002) of the psychology of false confessions. The authors note that Kassin's review makes a compelling argument for the need for legal reform in police interrogation practices. Because his work strikes at the heart of the American criminal justice system--its fairness--the…

  8. Sleep deprivation and false confessions

    PubMed Central

    Frenda, Steven J.; Berkowitz, Shari R.; Loftus, Elizabeth F.; Fenn, Kimberly M.

    2016-01-01

    False confession is a major contributor to the problem of wrongful convictions in the United States. Here, we provide direct evidence linking sleep deprivation and false confessions. In a procedure adapted from Kassin and Kiechel [(1996) Psychol Sci 7(3):125–128], participants completed computer tasks across multiple sessions and repeatedly received warnings that pressing the “Escape” key on their keyboard would cause the loss of study data. In their final session, participants either slept all night in laboratory bedrooms or remained awake all night. In the morning, all participants were asked to sign a statement, which summarized their activities in the laboratory and falsely alleged that they pressed the Escape key during an earlier session. After a single request, the odds of signing were 4.5 times higher for the sleep-deprived participants than for the rested participants. These findings have important implications and highlight the need for further research on factors affecting true and false confessions. PMID:26858426

  9. Sleep loss produces false memories.

    PubMed

    Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich

    2008-01-01

    People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",...), lacking the strongest common associate or theme word (here: "black"). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.

  10. False Positive Mammograms and Detection Controlled Estimation

    PubMed Central

    Kleit, Andrew N; Ruiz, James F

    2003-01-01

    Objective To investigate the causes of false positive in mammograms. Data Sources Secondary data collected from extracts from computerized medical records from 1999 from five thousand patients at a single hospital in a medium-sized Southern city. Study Design Retrospective analysis of electronic medical data on screening and diagnostic mammograms. Detection-controlled estimation (DCE) was used to compare the efficacy of alternative readers of mammogram films. Analysis was also conducted on follow-up exams of women who tested positive in the first stage of investigation. Key variables included whether the patient had had a prior mammogram, age of the patient, and identifiers for the individual physicians. Data Collection/Extraction Methods Hospital maintains electronic medical records (EMR) on all patients. Extracts were performed on this EMR system under the guidance of clinical expertise. Data were collected for all women who had mammograms in 1999. Random samples were employed for screening mammograms, and all data was used for diagnostic mammograms. Principal Findings Study results imply that access to a previous mammogram greatly reduces the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography. Were previous mammograms always available, the results imply the number of false positives would decrease by at least half. The results here also indicate that there is no reason to believe this decrease in false positive would be accompanied by an increase in the number of false negatives. Other attributes also affected the number of false positives. Mondays and Wednesdays appear to be more prone to false positives than the other days in the week. There is also some disparity in false positive outcomes among the five physicians studied. With respect to detection-controlled estimation, the results are mixed. With follow-up data, the DCE estimator appears to generate reasonable, robust

  11. Dividing attention lowers children's but increases adults' false memories.

    PubMed

    Otgaar, Henry; Peters, Maarten; Howe, Mark L

    2012-01-01

    The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a divided attention task. The results showed that divided attention affected children's and adults' false memory levels differently but did not alter true memory differently. Our results revealed a developmental shift in that divided attention lowered children's false memory rates but increased adults' false memory rates, regardless of the nature of the material (i.e., neutral or negative). Our study indicates that manipulations that target conscious processing (e.g., divided attention) result in marked qualitative and quantitative differences between children's and adults' false memories but not true memories.

  12. Outcome Knowledge and False Belief

    PubMed Central

    Ghrear, Siba E.; Birch, Susan A. J.; Bernstein, Daniel M.

    2016-01-01

    Virtually every social interaction involves reasoning about the perspectives of others, or ‘theory of mind (ToM).’ Previous research suggests that it is difficult to ignore our current knowledge when reasoning about a more naïve perspective (i.e., the curse of knowledge). In this Mini Review, we discuss the implications of the curse of knowledge for certain aspects of ToM. Particularly, we examine how the curse of knowledge influences key measurements of false belief reasoning. In closing, we touch on the need to develop new measurement tools to discern the mechanisms involved in the curse of knowledge and false belief reasoning, and how they develop across the lifespan. PMID:26903922

  13. Does sleep promote false memories?

    PubMed

    Darsaud, Annabelle; Dehon, Hedwige; Lahl, Olaf; Sterpenich, Virginie; Boly, Mélanie; Dang-Vu, Thanh; Desseilles, Martin; Gais, Stephen; Matarazzo, Luca; Peters, Frédéric; Schabus, Manuel; Schmidt, Christina; Tinguely, Gilberte; Vandewalle, Gilles; Luxen, André; Maquet, Pierre; Collette, Fabienne

    2011-01-01

    Memory is constructive in nature so that it may sometimes lead to the retrieval of distorted or illusory information. Sleep facilitates accurate declarative memory consolidation but might also promote such memory distortions. We examined the influence of sleep and lack of sleep on the cerebral correlates of accurate and false recollections using fMRI. After encoding lists of semantically related word associates, half of the participants were allowed to sleep, whereas the others were totally sleep deprived on the first postencoding night. During a subsequent retest fMRI session taking place 3 days later, participants made recognition memory judgments about the previously studied associates, critical theme words (which had not been previously presented during encoding), and new words unrelated to the studied items. Sleep, relative to sleep deprivation, enhanced accurate and false recollections. No significant difference was observed in brain responses to false or illusory recollection between sleep and sleep deprivation conditions. However, after sleep but not after sleep deprivation (exclusive masking), accurate and illusory recollections were both associated with responses in the hippocampus and retrosplenial cortex. The data suggest that sleep does not selectively enhance illusory memories but rather tends to promote systems-level consolidation in hippocampo-neocortical circuits of memories subsequently associated with both accurate and illusory recollections. We further observed that during encoding, hippocampal responses were selectively larger for items subsequently accurately retrieved than for material leading to illusory memories. The data indicate that the early organization of memory during encoding is a major factor influencing subsequent production of accurate or false memories.

  14. Linguistic Determinants of the Difficulty of True-False Test Items

    ERIC Educational Resources Information Center

    Peterson, Candida C.; Peterson, James L.

    1976-01-01

    Adults read a prose passage and responded to passages based on it which were either true or false and were phrased either affirmatively or negatively. True negatives yielded most errors, followed in order by false negatives, true affirmatives, and false affirmatives. (Author/RC)

  15. Dividing Attention Lowers Children's but Increases Adults' False Memories

    ERIC Educational Resources Information Center

    Otgaar, Henry; Peters, Maarten; Howe, Mark L.

    2012-01-01

    The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a…

  16. False advertising in the greenhouse?

    NASA Astrophysics Data System (ADS)

    Banse, K.

    1991-12-01

    Most scientists are convinced of the importance of their own research subjects. Broecker [1991] has deplored the temptation, if not the tendency, to go overboard and exaggerate this importance once funding enters the mind. In particular, he alleges inflated or even false claims by biological (and other) oceanographers regarding the relevance of their research to the "greenhouse effect," caused by the anthropogenic enhancement of the atmospheric CO2 content. He writes [Broecker, 1991, p. 191]: "In my estimation, on any list of subjects requiring intense study with regard to the prediction of the consequences of CO2 buildup in the atmosphere, I would place marine biological cycles near the bottom."

  17. Valence, Implicated Actor, and Children's Acquiescence to False Suggestions.

    PubMed

    Cleveland, Kyndra C; Quas, Jodi A; Lyon, Thomas D

    2016-01-01

    Although adverse effects of suggestive interviewing on children's accuracy are well documented, it remains unclear as to whether these effects vary depending on the valence of and the actor implicated in suggestions. In this study, 124 3-8-year-olds participated in a classroom activity and were later questioned about positive and negative false details. The interviewer provided positive reinforcement when children acquiesced to suggestions and negative feedback when they did not. Following reinforcement or feedback, young children were comparably suggestible for positive and negative details. With age, resistance to suggestions about negative details emerged first, followed by resistance to suggestions about positive details. Across age, more negative feedback was required to induce acquiescence to negative than positive false details. Finally, children were less willing to acquiesce when they (versus the confederate) were implicated. Findings highlight the interactive effects of valence and children's age on their eyewitness performance in suggestive contexts.

  18. Simulating runoff under changing climatic conditions: Revisiting an apparent deficiency of conceptual rainfall-runoff models

    NASA Astrophysics Data System (ADS)

    Fowler, Keirnan J. A.; Peel, Murray C.; Western, Andrew W.; Zhang, Lu; Peterson, Tim J.

    2016-03-01

    Hydrologic models have potential to be useful tools in planning for future climate variability. However, recent literature suggests that the current generation of conceptual rainfall runoff models tend to underestimate the sensitivity of runoff to a given change in rainfall, leading to poor performance when evaluated over multiyear droughts. This research revisited this conclusion, investigating whether the observed poor performance could be due to insufficient model calibration and evaluation techniques. We applied an approach based on Pareto optimality to explore trade-offs between model performance in different climatic conditions. Five conceptual rainfall runoff model structures were tested in 86 catchments in Australia, for a total of 430 Pareto analyses. The Pareto results were then compared with results from a commonly used model calibration and evaluation method, the Differential Split Sample Test. We found that the latter often missed potentially promising parameter sets within a given model structure, giving a false negative impression of the capabilities of the model. This suggests that models may be more capable under changing climatic conditions than previously thought. Of the 282[347] cases of apparent model failure under the split sample test using the lower [higher] of two model performance criteria trialed, 155[120] were false negatives. We discuss potential causes of remaining model failures, including the role of data errors. Although the Pareto approach proved useful, our aim was not to suggest an alternative calibration strategy, but to critically assess existing methods of model calibration and evaluation. We recommend caution when interpreting split sample results.

  19. Identification and resection of the clipped node decreases the false negative rate of sentinel lymph node surgery in patients presenting with node positive breast cancer (T0-T4, N1-2) who receive neoadjuvant chemotherapy – results from ACOSOG Z1071 (Alliance)

    PubMed Central

    Boughey, Judy C.; Ballman, Karla V.; Le-Petross, Huong T.; McCall, Linda M.; Mittendorf, Elizabeth A.; Ahrendt, Gretchen M.; Wilke, Lee G.; Taback, Bret; Feliberti, Eric C.; Hunt, Kelly K.

    2015-01-01

    Background The American College of Surgeons Oncology Group Z1071 trial reported a false negative rate (FNR) of 12.6% with sentinel lymph node (SLN) surgery after neoadjuvant chemotherapy in women presenting with node-positive breast cancer. One proposed method to decrease the FNR is clip placement in the positive node at initial diagnosis with confirmation of clipped node resection at surgery. Methods Z1071 was a multi-institutional trial in which women with clinical T0-4,N1-2,M0 breast cancer underwent SLN surgery and axillary dissection (ALND) after neoadjuvant chemotherapy. In cases with a clip placed in the node, the clip location at surgery (SLN or ALND) was evaluated. Results A clip was placed at initial node biopsy in 203 patients. In the 170 (83.7%) patients with cN1 disease and at least 2 SLNs resected, clip location was confirmed in 141 cases. In 107 (75.9%) patients where the clipped node was within the SLN specimen, the FNR was 6.8% (CI:1.9–16.5%). In 34 (24.1%) cases where the clipped node was in the ALND specimen, the FNR was 19.0% (CI:5.4–41.9%). In cases without a clip placed (n=355) and those where clipped node location was not confirmed at surgery (n=29), the FNR was 13.4% and 14.3%, respectively. Conclusion Clip placement at diagnosis of node-positive disease with removal of the clipped node during SLN surgery reduces the FNR of SLN surgery after neoadjuvant chemotherapy. Clip placement in the biopsy-proven node at diagnosis and evaluation of resected specimens for the clipped node should be considered when performing SLN surgery in this setting. PMID:26649589

  20. Cape Verde in False Color

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this false-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days.

    This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  1. Discrete emotion-congruent false memories in the DRM paradigm.

    PubMed

    Bland, Cassandra E; Howe, Mark L; Knott, Lauren

    2016-08-01

    Research has shown that false-memory production is enhanced for material that is emotionally congruent with the mood of the participant at the time of encoding. So far this research has only been conducted to examine the influence of generic negative affective mood states and generic negative stimuli on false-memory production. In addition, much of the research is limited as it focuses on valence and arousal dimensions, and fails to take into account the more comprehensive nature of emotions. The current study demonstrates that this effect goes beyond general negative or positive moods and acts at a more discrete emotional level. Participants underwent a standard emotion-induction procedure before listening to negative emotional or neutral associative word lists. The emotions induced, negative word lists, and associated nonpresented critical lures, were related to either fear or anger, 2 negative valence emotions that are also both high in arousal. Results showed that when valence and arousal are controlled for, false memories are more likely to be produced for discrete emotionally congruent compared with incongruent materials. These results support spreading activation theories of false remembering and add to our understanding of the adaptive nature of false-memory production. (PsycINFO Database Record

  2. Dusty Crater In False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This false color image of a crater rim illustrates just how complete the dust cover can be. The small white/blue regions on the rim are of areas where the dust cover has been removed - due to heating on sun facing slopes or by gravitational effects.

    Image information: VIS instrument. Latitude 70.1, Longitude 352.8 East (7.2 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. False-color Dalmatian Terrain

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 10 May 2004 This daytime visible color image was collected on May 18, 2003 during the Southern Spring season in Noachis Terra.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -74, Longitude 351.9 East (8.1 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space

  4. An apparent hiatus in global warming?

    NASA Astrophysics Data System (ADS)

    Trenberth, Kevin E.; Fasullo, John T.

    2013-12-01

    Global warming first became evident beyond the bounds of natural variability in the 1970s, but increases in global mean surface temperatures have stalled in the 2000s. Increases in atmospheric greenhouse gases, notably carbon dioxide, create an energy imbalance at the top-of-atmosphere (TOA) even as the planet warms to adjust to this imbalance, which is estimated to be 0.5-1 W m-2 over the 2000s. Annual global fluctuations in TOA energy of up to 0.2 W m-2 occur from natural variations in clouds, aerosols, and changes in the Sun. At times of major volcanic eruptions the effects can be much larger. Yet global mean surface temperatures fluctuate much more than these can account for. An energy imbalance is manifested not just as surface atmospheric or ground warming but also as melting sea and land ice, and heating of the oceans. More than 90% of the heat goes into the oceans and, with melting land ice, causes sea level to rise. For the past decade, more than 30% of the heat has apparently penetrated below 700 m depth that is traceable to changes in surface winds mainly over the Pacific in association with a switch to a negative phase of the Pacific Decadal Oscillation (PDO) in 1999. Surface warming was much more in evidence during the 1976-1998 positive phase of the PDO, suggesting that natural decadal variability modulates the rate of change of global surface temperatures while sea-level rise is more relentless. Global warming has not stopped; it is merely manifested in different ways.

  5. The false classification of extinction risk in noisy environments

    PubMed Central

    Connors, B. M.; Cooper, A. B.; Peterman, R. M.; Dulvy, N. K.

    2014-01-01

    Abundance trends are the basis for many classifications of threat and recovery status, but they can be a challenge to interpret because of observation error, stochastic variation in abundance (process noise) and temporal autocorrelation in that process noise. To measure the frequency of incorrectly detecting a decline (false-positive or false alarm) and failing to detect a true decline (false-negative), we simulated stable and declining abundance time series across several magnitudes of observation error and autocorrelated process noise. We then empirically estimated the magnitude of observation error and autocorrelated process noise across a broad range of taxa and mapped these estimates onto the simulated parameter space. Based on the taxa we examined, at low classification thresholds (30% decline in abundance) and short observation windows (10 years), false alarms would be expected to occur, on average, about 40% of the time assuming density-independent dynamics, whereas false-negatives would be expected to occur about 60% of the time. However, false alarms and failures to detect true declines were reduced at higher classification thresholds (50% or 80% declines), longer observation windows (20, 40, 60 years), and assuming density-dependent dynamics. The lowest false-positive and false-negative rates are likely to occur for large-bodied, long-lived animal species. PMID:24898368

  6. Mood-congruent true and false memory: effects of depression.

    PubMed

    Howe, Mark L; Malone, Catherine

    2011-02-01

    The Deese/Roediger-McDermott paradigm was used to investigate the effect of depression on true and false recognition. In this experiment true and false recognition was examined across positive, neutral, negative, and depression-relevant lists for individuals with and without a diagnosis of major depressive disorder. Results showed that participants with major depressive disorder falsely recognised significantly more depression-relevant words than non-depressed controls. These findings also parallel recent research using recall instead of recognition and show that there are clear mood congruence effects for depression on false memory performance.

  7. Dynamics of false vacuum bubbles in Brans-Dicke theory

    SciTech Connect

    Lee, Bum-Hoon; Lee, Wonwoo; Yeom, Dong-han E-mail: warrior@sogang.ac.kr

    2011-01-01

    We study the dynamics of false vacuum bubbles in the Brans-Dicke theory of gravity by using the thin shell or thin wall approximation. We consider a false vacuum bubble that has a different value for the Brans-Dicke field between the inside false vacuum region and the outside true vacuum region. Within a certain limit of field values, the difference of field values makes the effective tension of the shell negative. This allows new expanding false vacuum bubbles to be seen by the outside observer, which are disallowed in Einstein gravity.

  8. Caffeine's effects on true and false memory.

    PubMed

    Capek, Sarah; Guenther, R Kim

    2009-06-01

    Caffeine's effects on recall of word lists were investigated using the Deese-Roediger-McDermott (DRM) paradigm. College students were administered either 200 mg of caffeine or a 250-mg lactose placebo; after 30 min., they were tested on recall using six word lists. Words of each list were semantically related to a single word (a "critical lure") that was not presented in the list. Participants administered caffeine recalled more list words and more critical lures than participants administered lactose. Recall of list words was negatively correlated with recall of critical lures. Caffeine appears to intensify the strength of connections among list words and critical lures, thereby enhancing both true and false memory.

  9. Ice Surfaces In False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This full resolution image shows a marked difference in the 'blueness' of the ice surfaces. The lower (presumably older) surface is oranger and the top (presumably younger) surface is blue. This may represent the fresher ice of the upper surface which has not yet covered with as much dust as the lower surface.

    Image information: VIS instrument. Latitude 80.8, Longitude 302.1 East (57.9 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Polar Layers in False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This image again illustrates the oranger/bluer nature of the polar layers.

    Image information: VIS instrument. Latitude 80.6, Longitude 70.2 East (289.8 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Sand Sea in False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This image is of part of the northern sand sea. The small dunes in the image are bluer than the ice/dust filled central crater.

    Image information: VIS instrument. Latitude 73.7, Longitude 323 East (37 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Mimas Showing False Colors #2

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This false color image of Saturn's moon Mimas reveals variation in either the composition or texture across its surface.

    During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).

    This image is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined with a single black and white picture that isolates and maps regional color differences to create the final product.

    Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.

    Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of the image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil.

    This image was obtained when the Cassini spacecraft was above 25 degrees south, 134 degrees west latitude and longitude. The Sun-Mimas-spacecraft angle was 45 degrees and north is at the top.

    The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian

  13. Southern Spring in False Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    The Odyssey spacecraft has completed a full Mars year of observations of the red planet. For the next several weeks the Image of the Day will look back over this first mars year. It will focus on four themes: 1) the poles - with the seasonal changes seen in the retreat and expansion of the caps; 2) craters - with a variety of morphologies relating to impact materials and later alteration, both infilling and exhumation; 3) channels - the clues to liquid surface flow; and 4) volcanic flow features. While some images have helped answer questions about the history of Mars, many have raised new questions that are still being investigated as Odyssey continues collecting data as it orbits Mars.

    This image was collected June 25, 2003 during the southern spring season. This false color image shows both the layered ice cap and darker 'spots' that are seen only when the sun first lights the polar surface.

    Image information: VIS instrument. Latitude -82.3, Longitude 306 East (54 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the

  14. Friedmann equations and thermodynamics of apparent horizons.

    PubMed

    Gong, Yungui; Wang, Anzhong

    2007-11-23

    With the help of a masslike function which has a dimension of energy and is equal to the Misner-Sharp mass at the apparent horizon, we show that the first law of thermodynamics of the apparent horizon dE=T(A)dS(A) can be derived from the Friedmann equation in various theories of gravity, including the Einstein, Lovelock, nonlinear, and scalar-tensor theories. This result strongly suggests that the relationship between the first law of thermodynamics of the apparent horizon and the Friedmann equation is not just a simple coincidence, but rather a more profound physical connection.

  15. Mimas Showing False Colors #1

    NASA Technical Reports Server (NTRS)

    2005-01-01

    False color images of Saturn's moon, Mimas, reveal variation in either the composition or texture across its surface.

    During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).

    The image at the left is a narrow angle clear-filter image, which was separately processed to enhance the contrast in brightness and sharpness of visible features. The image at the right is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined into a single black and white picture that isolates and maps regional color differences. This 'color map' was then superimposed over the clear-filter image at the left.

    The combination of color map and brightness image shows how the color differences across the Mimas surface materials are tied to geological features. Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.

    Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of each image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in

  16. Affect influences false memories at encoding: evidence from recognition data.

    PubMed

    Storbeck, Justin; Clore, Gerald L

    2011-08-01

    Memory is susceptible to illusions in the form of false memories. Prior research found, however, that sad moods reduce false memories. The current experiment had two goals: (1) to determine whether affect influences retrieval processes, and (2) to determine whether affect influences the strength and the persistence of false memories. Happy or sad moods were induced either before or after learning word lists designed to produce false memories. Control groups did not experience a mood induction. We found that sad moods reduced false memories only when induced before learning. Signal detection analyses confirmed that sad moods induced prior to learning reduced activation of nonpresented critical lures suggesting that they came to mind less often. Affective states, however, did not influence retrieval effects. We conclude that negative affective states promote item-specific processing, which reduces false memories in a similar way as using an explicitly guided cognitive control strategy.

  17. Publication bias and the canonization of false facts.

    PubMed

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin; Bergstrom, Carl T

    2016-12-20

    Science is facing a "replication crisis" in which many experimental findings cannot be replicated and are likely to be false. Does this imply that many scientific facts are false as well? To find out, we explore the process by which a claim becomes fact. We model the community's confidence in a claim as a Markov process with successive published results shifting the degree of belief. Publication bias in favor of positive findings influences the distribution of published results. We find that unless a sufficient fraction of negative results are published, false claims frequently can become canonized as fact. Data-dredging, p-hacking, and similar behaviors exacerbate the problem. Should negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims would be more readily distinguished. To the degree that the model reflects the real world, there may be serious concerns about the validity of purported facts in some disciplines.

  18. Allergen immunotherapy and allergic rhinitis: false beliefs

    PubMed Central

    2013-01-01

    Background Over the last 100 years, several persistent misconceptions or ‘false beliefs’ have built up around allergen immunotherapy and its use in allergic rhinitis. This is perhaps because enthusiastic physicians administered complex allergen extracts to a diverse population of patients suffering from heterogeneous atopic conditions. Here, we review evidence that counters seven of these ‘false beliefs.’ Discussion 1. The symptoms of allergic rhinitis can be more heterogeneous, more severe and more troublesome in everyday life than many physicians believe. Large-scale epidemiological surveys show that the majority of allergic rhinitis patients have at least one symptom severe enough to interfere with sleep quality, productivity and/or well-being. 2. Allergen immunotherapy is not necessarily suitable for all allergic rhinitis patients (notably those with mild symptoms). Recent evidence from double-blind, placebo-controlled, randomized clinical trials suggests that the more severe the disease, the greater the treatment effect. 3. Allergen immunotherapy is often accused of lack of efficacy (relative to pharmacotherapy, for example). However, there are now many meta-analyses, systematic reviews and high-quality clinical trials that find overwhelmingly in favor of the efficacy of allergen immunotherapy (including sublingual formulations) in allergic rhinitis induced by pollen and, increasingly, other allergens. 4. Natural-exposure and challenge-chamber trials have shown that symptom relief may become apparent within months or even weeks of the initiation of allergen immunotherapy. 5. In pollen-induced allergic rhinitis, several years of subcutaneous or sublingual allergen immunotherapy are associated with sustained clinical efficacy after subsequent treatment cessation – confirming the disease-modifying nature of this therapy. 6. Most patients seeking treatment for allergic rhinitis are polysensitized, and allergen immunotherapy has proven efficacy in large

  19. Thai Negation.

    ERIC Educational Resources Information Center

    Alam, Samsul

    A study analyzed the structure of negative sentences in the Thai language, based on data gathered from two native speakers. It is shown that the Thai negative marker generally occurs between the noun phrase (subject) and the verb phrase in simple active sentences and in passive sentences. Negation of noun phrases is also allowed in Thai, with a…

  20. High temperature strain gage apparent strain compensation

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K.; Moore, T. C., Sr.

    1992-01-01

    Once an installed strain gage is connected to a strain indicating device and the instrument is balanced, a subsequent change in temperature of the gage installation will generally produce a resistance change in the gage. This purely temperature-induced resistance will be registered by the indicating device as a strain and is referred to as 'apparent strain' to distinguish it from strain due to applied stress. One desirable technique for apparent strain compensation is to employ two identical gages with identical mounting procedures which are connected with a 'half bridge' configuration where gages see the same thermal environment but only one experiences a mechanical strain input. Their connection in adjacent arms of the bridge will then balance the thermally induced apparent strains and, in principle, only the mechanical strain remains. Two approaches that implement this technique are discussed.

  1. Effects of aging and education on false memory.

    PubMed

    Lee, Yuh-Shiow; Lee, Chia-Lin; Yang, Hua-Te

    2012-01-01

    This study examined the effects of aging and education on participants' false memory for words that were not presented. Three age groups of participants with either a high or low education level were asked to study lists of semantically related words. Both age and education were found to affect veridical and false memory, as indicated in the recall and recognition of the studied word and nonstudied lures. A low education level had a negative effect on memory performance for both young and middle-aged adults. Older adults with a high level of education had a higher level of false memory than those with a lower education level. The results of this study are discussed in terms of the importance of education on false memory and mechanisms that create false memory of words in older adults.

  2. 19 CFR 111.32 - False information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false False information. 111.32 Section 111.32 Customs... CUSTOMS BROKERS Duties and Responsibilities of Customs Brokers § 111.32 False information. A broker must... procure the giving of, any false or misleading information or testimony in any matter pending before...

  3. Emotion and false memory: The context-content paradox.

    PubMed

    Bookbinder, S H; Brainerd, C J

    2016-12-01

    False memories are influenced by a variety of factors, but emotion is a variable of special significance, for theoretical and practical reasons. Interestingly, emotion's effects on false memory depend on whether it is embedded in the content of to-be-remembered events or in our moods, where mood is an aspect of the context in which events are encoded. We sketch the theoretical basis for this content-context dissociation and then review accumulated evidence that content and context effects are indeed different. Paradoxically, we find that in experiments on spontaneous and implanted false memories, negatively valenced content foments distortion, but negatively valenced moods protect against it. In addition, correlational data show that enduring negative natural moods (e.g., depression) foment false memory. Current opponent-process models of false memory, such as fuzzy-trace theory, are able to explain the content-context dissociation: Variations in emotional content primarily affect memory for the gist of events, whereas variations in emotional context primarily affect memory for events' exact verbatim form. Important questions remain about how these effects are modulated by variations in memory tests and in arousal. Promising methods of tackling those questions are outlined, especially designs that separate the gist and verbatim influences of emotion. (PsycINFO Database Record

  4. NEGATIVE SYMPTOMS AND NEGATIVE SCHIZOPHRENIA

    PubMed Central

    Chaturvedi, S.K.; Gopinath, P.S.; Mathai, P. John; Michael, Albert

    1984-01-01

    SUMMARY This study determines the frequency distribution of prominent negative symptoms in a group of chronic, hospitalised schizophrenics. Thirty chronic Schizophrenic (D.S.M. III) patients were rated on the scale for Assessment of Negative Symptoms (SANS) and the prominent negative symptoms were correlated with age, sex and certain illness variables. Majority (80%) of patients had some or the other negative symptom, except thought blocking which was found in none. The subjective awareness of the symptoms was poor. Most negative symptoms were present to a severe degree in about 40% of cases. However, no significant correlation was found between severe negative symptoms and age or sex. Similarly, duration of illness, duration of hospitalisation or current medications did not influence negative symptoms to any appreciable degree. The implications are discussed. PMID:21965985

  5. Ectopic pregnancy in an apparently healthy bitch.

    PubMed

    Eddey, Philip D

    2012-01-01

    This case describes an extrauterine fetus that was discovered in an apparently healthy bitch 5 mo after whelping. The extrauterine fetus was surgically removed, and the bitch made a complete recovery. The topic of canine ectopic pregnancy is discussed, and a review of previously reported cases is presented.

  6. Means for improving apparent resolution of television

    NASA Technical Reports Server (NTRS)

    Hilborn, E. H.

    1967-01-01

    Technique using short term temporal integration characteristics of the observers visual system improves the apparent resolution of television video presentations. The raster is displaced slightly on each frame so the eye can integrate the information in each raster grain. This phase shift uses a switching time delay.

  7. Brain representations of negative numbers.

    PubMed

    Parnes, Michael; Berger, Andrea; Tzelgov, Joseph

    2012-12-01

    Participants performed a physical comparison task of pairs of positive and pairs of negative one-digit numbers while their electrophysiological brain activity was measured. The numerical value of the presented digits was either congruent or incongruent with the physical size of the digits. Analysis has shown that the earliest event-related potential (ERP) difference between positive and negative numbers was found in the P300 ERP component peak, where there was an inverse effect of congruity in the negative pairs, compared with the positive ones. This pattern of results supports the idea that natural numbers serve as primitives of the human cognitive system, whereas negative numbers are apparently generated if needed.

  8. The consequences of suggesting false childhood food events.

    PubMed

    Bernstein, Daniel M; Scoboria, Alan; Arnold, Robert

    2015-03-01

    We combined data across eight published experiments (N=1369) to examine the formation and consequences of false autobiographical beliefs and memories. Our path models revealed that the formation of false autobiographical belief fully mediated the pathway between suggesting to people that they had experienced a positive or negative food-related event in the past and current preference for that food. Suggestion indirectly affected intention to eat the food via change in autobiographical belief. The development of belief with and without memory produced similar changes in food preferences and behavior intention, indicating that belief in the event drives changes in suggestion-related attitudes. Finally, positive suggestions (e.g., "you loved asparagus the first time you tried it") yielded stronger effects than negative suggestions (e.g., "you got sick eating egg salad"). These findings show that false autobiographical suggestions lead to the development of autobiographical beliefs, which in turn, have consequences for one's attitudes and behaviors.

  9. Affective false memories in Dementia of Alzheimer's Type.

    PubMed

    Fairfield, Beth; Colangelo, Mirco; Mammarella, Nicola; Di Domenico, Alberto; Cornoldi, Cesare

    2017-03-01

    This study examined the production of inferential false memories for complex pictorial stimuli and the implications of affective content in Alzheimer's disease (AD). A group of 24 AD patients and a group of 24 healthy older adults studied a sequence of pictures depicting stories that included positive, negative or neutral consequences of an unseen action, and then completed an old-new picture recognition test. The number of causal errors was higher in healthy older adults compared to AD patients but affective content attenuated the effect. Causal errors increased in AD patients when stories included affective (positive or negative) outcomes. In addition, negative content produced a larger number of errors than positive content across groups. This data confirms that although memory processing is poorer in AD, it is sensitive to affective content. Accordingly, the nature of affective false memory errors suggest the need to consider the use of affective information in the development of new cognitive training procedures.

  10. Geophysics Fatally Flawed by False Fundamental Philosophy

    NASA Astrophysics Data System (ADS)

    Myers, L. S.

    2004-05-01

    volcanoes, that enable planetary expansion the same way cranial sutures permit human skulls to grow to maturity. Expansion is shown by the Asian and Australian trenches, from Kamchatka to the Marianas, and from Samoa to the tip of Macquarie Ridge south of New Zealand, that are mirror images of the western coasts of North and South America. This is clear evidence neither the Atlantic nor the Pacific Ocean existed 250 Ma when Earth was much smaller. In just 250 Ma external accretion and internal core expansion increased Earth's diameter from 7640 km to 12,735 km and increased total surface area to 361,060,000 sq. km, the area occupied by today's oceans-oceans that did not exist 250 Ma when Earth was slightly larger than Mars is today \\(6787 km\\). The fallacy of the nebular hypothesis did not become apparent until after Oliver and Isacks introduced the concept of subduction in 1967. Subduction was based on the false assumption that Earth's diameter is constant and unchanging, and spawned the theory of Plate Tectonics that "revolutionized" geophysics in a short period of time-a "revolution" destined for failure. Evidence is presented showing all solar bodies originate as comets \\(fragments of supernovae explosions\\) captured by the Sun that become meteoroids or asteroids by external accretion of meteorites and dust from over 370 known meteor streams.\\(Terentjeva, 1964\\) Accreation replaces the nebular hypothesis and rejuvenates Carey's Earth Expansion theory that, unfortunately, was pushed aside by plate tectonics because it lacked a plausible mechanism. However, expansion carries an ultimate threat to Mankind's tenure on Earth and exploration of Mars as the future home of Mankind takes on added significance.

  11. Frog Swarms: Earthquake Precursors or False Alarms?

    PubMed Central

    Grant, Rachel A.; Conlan, Hilary

    2013-01-01

    Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by

  12. Accounting for False Positive HIV Tests: Is Visceral Leishmaniasis Responsible?

    PubMed Central

    Shanks, Leslie; Ritmeijer, Koert; Piriou, Erwan; Siddiqui, M. Ruby; Kliescikova, Jarmila; Pearce, Neil; Ariti, Cono; Muluneh, Libsework; Masiga, Johnson; Abebe, Almaz

    2015-01-01

    Background Co-infection with HIV and visceral leishmaniasis is an important consideration in treatment of either disease in endemic areas. Diagnosis of HIV in resource-limited settings relies on rapid diagnostic tests used together in an algorithm. A limitation of the HIV diagnostic algorithm is that it is vulnerable to falsely positive reactions due to cross reactivity. It has been postulated that visceral leishmaniasis (VL) infection can increase this risk of false positive HIV results. This cross sectional study compared the risk of false positive HIV results in VL patients with non-VL individuals. Methodology/Principal Findings Participants were recruited from 2 sites in Ethiopia. The Ethiopian algorithm of a tiebreaker using 3 rapid diagnostic tests (RDTs) was used to test for HIV. The gold standard test was the Western Blot, with indeterminate results resolved by PCR testing. Every RDT screen positive individual was included for testing with the gold standard along with 10% of all negatives. The final analysis included 89 VL and 405 non-VL patients. HIV prevalence was found to be 12.8% (47/ 367) in the VL group compared to 7.9% (200/2526) in the non-VL group. The RDT algorithm in the VL group yielded 47 positives, 4 false positives, and 38 negatives. The same algorithm for those without VL had 200 positives, 14 false positives, and 191 negatives. Specificity and positive predictive value for the group with VL was less than the non-VL group; however, the difference was not found to be significant (p = 0.52 and p = 0.76, respectively). Conclusion The test algorithm yielded a high number of HIV false positive results. However, we were unable to demonstrate a significant difference between groups with and without VL disease. This suggests that the presence of endemic visceral leishmaniasis alone cannot account for the high number of false positive HIV results in our study. PMID:26161864

  13. An Association Account of False Belief Understanding

    ERIC Educational Resources Information Center

    De Bruin, L. C.; Newen, A.

    2012-01-01

    The elicited-response false belief task has traditionally been considered as reliably indicating that children acquire an understanding of false belief around 4 years of age. However, recent investigations using spontaneous-response tasks suggest that false belief understanding emerges much earlier. This leads to a developmental paradox: if young…

  14. 20 CFR 356.3 - False claims.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false False claims. 356.3 Section 356.3 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS OR STATEMENTS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 356.3 False claims. In the case of penalties assessed under 31...

  15. 20 CFR 356.3 - False claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false False claims. 356.3 Section 356.3 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS OR STATEMENTS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 356.3 False claims. In the case of penalties assessed under 31...

  16. 30 CFR 281.5 - False statements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false False statements. 281.5 Section 281.5 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 281.5 False statements. Under...

  17. Apparent extended body motions in depth

    NASA Technical Reports Server (NTRS)

    Hecht, Heiko; Proffitt, Dennis R.

    1991-01-01

    Five experiments were designed to investigate the influence of three-dimensional (3-D) orientation change on apparent motion. Projections of an orientation-specific 3-D object were sequentially flashed in different locations and at different orientations. Such an occurrence could be resolved by perceiving a rotational motion in depth around an axis external to the object. Consistent with this proposal, it was found that observers perceived curved paths in depth. Although the magnitude of perceived trajectory curvature often fell short of that required for rotational motions in depth (3-D circularity), judgments of the slant of the virtual plane on which apparent motions occurred were quite close to the predictions of a model that proposes circular paths in depth.

  18. Predicting apparent Sherwood numbers for fluidized beds

    SciTech Connect

    Groenewold, H.; Tsotsas, E.

    1999-09-01

    Mass transfer data of bubbling fluidized beds have been reevaluated with a new model which is completely predictive. The model is based on a two-phase approach with active bypass, formally plug flow for the suspension gas and a consideration of backmixing in the main kinetic coefficient, i.e. in the apparent particle-to-fluid Sherwood number. A good agreement with experimental results of various authors with a broad range of Reynolds numbers and particle diameters is demonstrated.

  19. Comment: An Apparent Controversy in Auroral Physics

    NASA Astrophysics Data System (ADS)

    Haerendel, Gerhard

    2007-03-01

    In his article ``A turning point in auroral physics,'' Bryant argued against what he called the `standard' theory of auroral acceleration, according to which the electrons ``gain their energy from static electric fields,'' and offered wave acceleration as an alternative. Because of the importance of the process, not only for the aurora borealis but also for other cosmic plasmas, a clarification of this apparent controversy seems to be in place.

  20. Apparent exchange rate mapping with diffusion MRI.

    PubMed

    Lasič, Samo; Nilsson, Markus; Lätt, Jimmy; Ståhlberg, Freddy; Topgaard, Daniel

    2011-08-01

    Water exchange through the cell membranes is an important feature of cells and tissues. The rate of exchange is determined by factors such as membrane lipid composition and organization, as well as the type and activity of aquaporins. A method for noninvasively estimating the rate of water exchange would be useful for characterizing pathological conditions, e.g., tumors, multiple sclerosis, and ischemic stroke, expected to be associated with a change of the membrane barrier properties. This study describes the filter exchange imaging method for determining the rate of water exchange between sites having different apparent diffusion coefficients. The method is based on the filter-exchange pulsed gradient spin-echo NMR spectroscopy experiment, which is here modified to be compatible with the constraints of clinical MR scanners. The data is analyzed using a model-free approach yielding maps of the apparent exchange rate, here being introduced in analogy with the concept of the apparent diffusion coefficient. Proof-of-principle experiments are performed on microimaging and whole-body clinical scanners using yeast suspension phantoms. The limitations and appropriate experimental conditions are examined. The results demonstrate that filter exchange imaging is a fast and reliable method for characterizing exchange, and that it has the potential to become a powerful diagnostic tool.

  1. False discoveries and models for gene discovery.

    PubMed

    van den Oord, Edwin J C G; Sullivan, Patrick F

    2003-10-01

    In the search for genes underlying complex traits, there is a tendency to impose increasingly stringent criteria to avoid false discoveries. These stringent criteria make it hard to find true effects, and we argue that it might be better to optimize our procedures for eliminating and controlling false discoveries. Focusing on achieving an acceptable ratio of true- and false-positives, we show that false discoveries could be eliminated much more efficiently using a stepwise approach. To avoid a relatively high false discovery rate, corrections for 'multiple testing' might also be needed in candidate gene studies. If the appropriate methods are used, detecting the proportion of true effects appears to be a more important determinant of the genotyping burden than the desired false discovery rate. This raises the question of whether current models for gene discovery are shaped excessively by a fear of false discoveries.

  2. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  3. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  4. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  5. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  6. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  7. Apparent Geocenter Variations from IGS Analysis

    NASA Astrophysics Data System (ADS)

    Ferland, R.

    2001-12-01

    Natural Resources Canada's (NRCan) Geodetic Survey Division (GSD), on behalf of the International GPS Service (IGS) and its Reference Frame Working Group, combines a consistent set of station coordinates, velocities, Earth Rotation Parameters (ERP) and apparent geocenter to produce the IGS official station position/ERP solutions in the Software Independent Exchange (SINEX) format The weekly Analysis Centers (AC) solutions include estimates of weekly station coordinates, apparent geocenter positions and daily ERPs. All the AC products are required to be in a consistent reference frame. The combination of station coordinates originating from different ACs involves removing all available constraints and re-scaling the covariance information. The weekly combination generally includes estimates of coordinates for 120 to 140 globally distributed stations. While the cumulative solution currently includes approximately 280 stations, about 215 of them have complete information and reliable velocity estimates. The IGS combined products are required to be consistent with the most recent realization of ITRF (currently ITRF97, soon in ITRF2000). This is done by transforming the weekly and cumulative solutions, respectively using 7 and 14 Helmert transformation parameters (3 translations, 3 rotations, 1 scale and their respective rates). The transformation parameters are determined from a subset of 51 high quality, globally distributed and generally collocated (with other space techniques) stations, also known as Reference Frame (RF) stations. The weekly estimated IGS apparent geocenter for the period between 99/08/01 (Wk 1012) and 01/08/04 (Wk 1025) has been analyzed. The apparent X, Y and Z geocenter components were estimated with respect to the realization of ITRF97. The estimated weekly geocenter positions relied on COD, ESA and JPL SINEX solutions for the period of interest. The formal error for the weekly geocenter is about 6-8mm for the XY components and 8-10mm for the Z

  8. Apparent magnitude of earthshine: a simple calculation

    NASA Astrophysics Data System (ADS)

    Agrawal, Dulli Chandra

    2016-05-01

    The Sun illuminates both the Moon and the Earth with practically the same luminous fluxes which are in turn reflected by them. The Moon provides a dim light to the Earth whereas the Earth illuminates the Moon with somewhat brighter light which can be seen from the Earth and is called earthshine. As the amount of light reflected from the Earth depends on part of the Earth and the cloud cover, the strength of earthshine varies throughout the year. The measure of the earthshine light is luminance, which is defined in photometry as the total luminous flux of light hitting or passing through a surface. The expression for the earthshine light in terms of the apparent magnitude has been derived for the first time and evaluated for two extreme cases; firstly, when the Sun’s rays are reflected by the water of the oceans and secondly when the reflector is either thick clouds or snow. The corresponding values are -1.30 and -3.69, respectively. The earthshine value -3.22 reported by Jackson lies within these apparent magnitudes. This paper will motivate the students and teachers of physics to look for the illuminated Moon by earthlight during the waning or waxing crescent phase of the Moon and to reproduce the expressions derived here by making use of the inverse-square law of radiation, Planck’s expression for the power in electromagnetic radiation, photopic spectral luminous efficiency function and expression for the apparent magnitude of a body in terms of luminous fluxes.

  9. Constructing rich false memories of committing crime.

    PubMed

    Shaw, Julia; Porter, Stephen

    2015-03-01

    Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive memory-retrieval techniques, participants were induced to generate criminal and noncriminal emotional false memories, and we compared these false memories with true memories of emotional events. After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components. It appears that in the context of a highly suggestive interview, people can quite readily generate rich false memories of committing crime.

  10. Apparent contact angle of an evaporating drop

    NASA Astrophysics Data System (ADS)

    Morris, S. J. S.

    2012-11-01

    In experiments by Poulard et al. (2005), a sessile drop of perfectly wetting liquid evaporates from a non-heated substrate into an under-saturated mixture of vapour with an inert gas; evaporation is limited by vapour diffusion. The system exhibits an apparent contact angle θ that is a flow property. Under certain conditions, the apparent contact line was stationary relative to the substrate; we predict θ for this case. Observed values of θ are small, allowing lubrication analysis of the liquid film. The liquid and vapour flows are coupled through conditions holding at the phase interface; in particular, vapour partial pressure there is related to the local value of liquid pressure through the Kelvin condition. Because the droplet is shallow, the interfacial conditions can be transferred to the solid-liquid interface at y = 0 . We show that the dimensionless partial pressure p (x , y) and the film thickness h (x) are determined by solving ∇2 p = 0 for y > 0 subject to a matching condition at infinity, and the conditions - p = L hxx +h-3 and (h3px) x + 3py = 0 at y = 0 . The parameter L controls the ratio of Laplace to disjoining pressure. We analyse this b.v.p. for the experimentally-relevant case L --> 0 .

  11. Apparent mass in viscous, vortical flows

    NASA Astrophysics Data System (ADS)

    Noca, Flavio

    2001-11-01

    The concept of added, virtual, apparent, or additional mass is well known in potential flow theory. It is added mass (or more exactly, the time derivative of virtual momentum) that wholly contributes to fluid dynamic forces in unsteady, potential flow configurations. While the force contribution from added mass can be easily evaluated in potential flows, it has always been thought that in real (vortical and viscous) flows, the contribution of added mass to the fluid dynamic force is intertwined in a complex way with the force resulting from wake and boundary layer vorticity. Recently, Shiels, Leonard, and Roshko (Journal of Fluids and Structures, vol 15, pp 3-21, 2001) [henceforth SLR] showed that the fluid dynamic lift force on a circular cylinder performing transverse oscillations in a steady stream can actually be decomposed into a lift force due to apparent mass (as evaluated from potential theory) and a ``wake'' force resulting from frictional as well as altered pressure forces caused by the boundary layer and wake growth in viscous flow. Through a rigorous formalism analogous to SLR’s, we will confirm that the SLR decomposition is correct and valid for any body shape in arbitrary motion. The SLR decomposition is a seminal discovery in the science of unsteady aero/hydrodynamics, as it allows to clearly distinguish the force contributions from added mass and from the ``wake''. The result is particularly important for understanding the flight and swimming mechanics of animals.

  12. False memory susceptibility is correlated with categorisation ability in humans

    PubMed Central

    Hunt, Kathryn; Chittka, Lars

    2014-01-01

    Our memory is often surprisingly inaccurate, with errors ranging from misremembering minor details of events to generating illusory memories of entire episodes. The pervasiveness of such false memories generates a puzzle: in the face of selection pressure for accuracy of memory, how could such systematic failures have persisted over evolutionary time? It is possible that memory errors are an inevitable by-product of our adaptive memories and that semantic false memories are specifically connected to our ability to learn rules and concepts and to classify objects by category memberships. Here we test this possibility using a standard experimental false memory paradigm and inter-individual variation in verbal categorisation ability. Indeed it turns out that the error scores are significantly negatively correlated, with those individuals scoring fewer errors on the categorisation test being more susceptible to false memory intrusions in a free recall test. A similar trend, though not significant, was observed between individual categorisation ability and false memory susceptibility in a word recognition task. Our results therefore indicate that false memories, to some extent, might be a by-product of our ability to learn rules, categories and concepts. PMID:25254105

  13. Use of aspartame by apparently healthy children and adolescents.

    PubMed

    Frey, G H

    1976-11-01

    This study was conducted to determine the effects and the differences, if any, resulting from the ingestion of aspartame (sweetener) versus sucrose. A 13-wk, double-blind study was conducted using 126 apparently healthy children and adolescents as panelists. Individuals were randomly assigned in a double-blind design to aspartame or sucrose in each of five age groups; dosage levels were assigned according to age and weight groups. Physical examinations and special eye examinations were performed at the beginning and end of the study. Other parameters determined including laboratory tests of liver and renal function, hematologic status, and plasma levels of phenylalanine and tyrosine. Clinically significant differences in laboratory parameters measured could not be demonstrated; all mean values were within normal limits. No unusual findings were observed in phenylalanine or tyrosine levels. All phenylpyruvic acid and methanol determinations were negative. No important physical changes occurred, and no product-related side effects were reported.

  14. Apparent Acceleration and an Alternative Concordance from Causal Backreaction

    NASA Astrophysics Data System (ADS)

    Bochner, Brett

    2015-01-01

    A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by cosmic structure formation, without resort to Dark Energy, modifications to gravity, or a local void. The observed acceleration results from the combined effect of innumerable local perturbations due to individually virializing systems, overlapping together in a smoothly-inhomogeneous adjustment of the FRW metric, in a process governed by the causal flow of inhomogeneity information outward from each clumped system. After noting how common arguments claiming to limit backreaction are physically unrealistic, models are presented which fit the supernova luminosity distance data essentially as well as ΛCDM, while bringing several important cosmological parameters to a new Concordance. These goals are all achieved with a second-generation version of our formalism that accounts for the negative feedback of Causal Backreaction upon itself due to the slowed propagation of gravitational inhomogeneity information.

  15. Explaining the Development of False Memories.

    ERIC Educational Resources Information Center

    Reyna, Valerie F.; Holliday, Robyn; Marche, Tammy

    2002-01-01

    Reviews explanatory dimensions of children's false memory relevant to forensic practice: measurement, development, social factors, individual differences, varieties of memories and memory judgments, and varieties of procedures inducing false memories. Asserts that recent studies fail to use techniques that separate acquiescence from memory…

  16. 15 CFR 80.6 - False statements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...

  17. 15 CFR 80.6 - False statements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...

  18. 15 CFR 80.6 - False statements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...

  19. 15 CFR 80.6 - False statements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...

  20. 15 CFR 80.6 - False statements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...

  1. How Does Distinctive Processing Reduce False Recall?

    ERIC Educational Resources Information Center

    Hunt, R. Reed; Smith, Rebekah E.; Dunlap, Kathryn R.

    2011-01-01

    False memories arising from associatively related lists are a robust phenomenon that resists many efforts to prevent it. However, a few variables have been shown to reduce this form of false memory. Explanations for how the reduction is accomplished have focused on either output monitoring processes or constraints on access, but neither idea alone…

  2. Can False Memories Prime Problem Solutions?

    ERIC Educational Resources Information Center

    Howe, Mark L.; Garner, Sarah R.; Dewhurst, Stephen A.; Ball, Linden J.

    2010-01-01

    Previous research has suggested that false memories can prime performance on related implicit and explicit memory tasks. The present research examined whether false memories can also be used to prime higher order cognitive processes, namely, insight-based problem solving. Participants were asked to solve a number of compound remote associate task…

  3. 30 CFR 281.5 - False statements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false False statements. 281.5 Section 281.5 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General §...

  4. Negative Certainty

    ERIC Educational Resources Information Center

    Ariso, José María

    2017-01-01

    The definitions of "negative knowledge" and the studies in this regard published to date have not considered the categorial distinction Wittgenstein established between knowledge and certainty. Hence, the important role that certainty, despite its omission, should have in these definitions and studies has not yet been shown. In this…

  5. Negative Numbers

    ERIC Educational Resources Information Center

    Galbraith, Mary J.

    1974-01-01

    Examination of models for representing integers demonstrates that formal operational thought is required for establishing the operations on integers. Advocated is the use of many models for introducing negative numbers but, apart from addition, it is recommended that operations on integers be delayed until the formal operations stage. (JP)

  6. Item method directed forgetting diminishes false memory.

    PubMed

    Marche, Tammy A; Brainerd, Charles J; Lane, David G; Loehr, Janeen D

    2005-10-01

    Directed forgetting may reduce DRM false memory illusion by interfering with meaning processing. Participants were presented with a list composed of six 10-word semantically associated sub-lists, and they were either (a) asked to remember all list items of (b) asked to remember all associates from sub-lists and to forget all associates from other sub-lists. All participants were requested to recall and recognise list items. Although directed forgetting effects have been previously reported only for true responses in the DRM paradigm with the list method, we also found directed forgetting for false responses with the item method. Such forgetting instructions reduced both verbatim and meaning processing, decreasing both the intrusion and the false alarm rate. These results are consistent with two-process explanations of DRM false memories, such as fuzzy-trace theory, and add to our understanding of false memory editing.

  7. Emotional content of true and false memories.

    PubMed

    Laney, Cara; Loftus, Elizabeth F

    2008-01-01

    Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants' pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood events were planted using a suggestive manipulation and then compared, along several subjective dimensions, with other participants' true memories. On most emotional dimensions (e.g., how emotional was this event for you?), true and false memories were indistinguishable. On a few measures (e.g., intensity of feelings at the time of the event), true memories were more emotional than false memories in the aggregate, yet true and false memories were equally likely to be rated as uniformly emotional. These results suggest that even substantial emotional content may not reliably indicate memory accuracy.

  8. Priming analogical reasoning with false memories.

    PubMed

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

  9. Rapid induction of false memory for pictures.

    PubMed

    Weinstein, Yana; Shanks, David R

    2010-07-01

    Recognition of pictures is typically extremely accurate, and it is thus unclear whether the reconstructive nature of memory can yield substantial false recognition of highly individuated stimuli. A procedure for the rapid induction of false memories for distinctive colour photographs is proposed. Participants studied a set of object pictures followed by a list of words naming those objects, but embedded in the list were names of unseen objects. When subsequently shown full colour pictures of these unseen objects, participants consistently claimed that they had seen them, while discriminating with high accuracy between studied pictures and new pictures whose names did not appear in the misleading word list. These false memories can be reported with high confidence as well as the feeling of recollection. This new procedure allows the investigation of factors that influence false memory reports with ecologically valid stimuli and of the similarities and differences between true and false memories.

  10. Social influence and mental routes to the production of authentic false memories and inauthentic false memories.

    PubMed

    Wagner, Michael F; Skowronski, John J

    2017-03-09

    Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others' summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants' memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts.

  11. Pluto behaving badly: false beliefs and their consequences.

    PubMed

    Berkowitz, Shari R; Laney, Cara; Morris, Erin K; Garry, Maryanne; Loftus, Elizabeth F

    2008-01-01

    We exposed college students to suggestive materials in order to lead them to believe that, as children, they had a negative experience at Disneyland involving the Pluto character. A sizable minority of subjects developed a false belief or memory that Pluto had uncomfortably licked their ear. Suggestions about a positive experience with Pluto led to even greater acceptance of a lovable ear-licking episode. False beliefs and memories had repercussions; those seduced by the bad suggestions were not willing to pay as much for a Pluto souvenir. These findings are among the first to demonstrate that false beliefs can have repercussions for people, meaning that they can influence their later thoughts, beliefs, and behaviors.

  12. On the susceptibility of adaptive memory to false memory illusions.

    PubMed

    Howe, Mark L; Derbish, Mary H

    2010-05-01

    Previous research has shown that survival-related processing of word lists enhances retention for that material. However, the claim that survival-related memories are more accurate has only been examined when true recall and recognition of neutral material has been measured. In the current experiments, we examined the adaptive memory superiority effect for different types of processing and material, measuring accuracy more directly by comparing true and false recollection rates. Survival-related information and processing was examined using word lists containing backward associates of neutral, negative, and survival-related critical lures and type of processing (pleasantness, moving, survival) was varied using an incidental memory paradigm. Across four experiments, results showed that survival-related words were more susceptible than negative and neutral words to the false memory illusion and that processing information in terms of its relevance to survival independently increased this susceptibility to the false memory illusion. Overall, although survival-related processing and survival-related information resulted in poorer, not more accurate, memory, such inaccuracies may have adaptive significance. These findings are discussed in the context of false memory research and recent theories concerning the importance of survival processing and the nature of adaptive memory.

  13. Publication bias and the canonization of false facts

    PubMed Central

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin; Bergstrom, Carl T

    2016-01-01

    Science is facing a “replication crisis” in which many experimental findings cannot be replicated and are likely to be false. Does this imply that many scientific facts are false as well? To find out, we explore the process by which a claim becomes fact. We model the community’s confidence in a claim as a Markov process with successive published results shifting the degree of belief. Publication bias in favor of positive findings influences the distribution of published results. We find that unless a sufficient fraction of negative results are published, false claims frequently can become canonized as fact. Data-dredging, p-hacking, and similar behaviors exacerbate the problem. Should negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims would be more readily distinguished. To the degree that the model reflects the real world, there may be serious concerns about the validity of purported facts in some disciplines. DOI: http://dx.doi.org/10.7554/eLife.21451.001 PMID:27995896

  14. Computing the apparent centroid of radar targets

    SciTech Connect

    Lee, C.E.

    1996-12-31

    A high-frequency multibounce radar scattering code was used as a simulation platform for demonstrating an algorithm to compute the ARC of specific radar targets. To illustrate this simulation process, several targets models were used. Simulation results for a sphere model were used to determine the errors of approximation associated with the simulation; verifying the process. The severity of glint induced tracking errors was also illustrated using a model of an F-15 aircraft. It was shown, in a deterministic manner, that the ARC of a target can fall well outside its physical extent. Finally, the apparent radar centroid simulation based on a ray casting procedure is well suited for use on most massively parallel computing platforms and could lead to the development of a near real-time radar tracking simulation for applications such as endgame fuzing, survivability, and vulnerability analyses using specific radar targets and fuze algorithms.

  15. Viscoelastic properties of the false vocal fold

    NASA Astrophysics Data System (ADS)

    Chan, Roger W.

    2004-05-01

    The biomechanical properties of vocal fold tissues have been the focus of many previous studies, as vocal fold viscoelasticity critically dictates the acoustics and biomechanics of phonation. However, not much is known about the viscoelastic response of the ventricular fold or false vocal fold. It has been shown both clinically and in computer simulations that the false vocal fold may contribute significantly to the aerodynamics and sound generation processes of human voice production, with or without flow-induced oscillation of the false fold. To better understand the potential role of the false fold in phonation, this paper reports some preliminary measurements on the linear and nonlinear viscoelastic behavior of false vocal fold tissues. Linear viscoelastic shear properties of human false fold tissue samples were measured by a high-frequency controlled-strain rheometer as a function of frequency, and passive uniaxial tensile stress-strain response of the tissue samples was measured by a muscle lever system as a function of strain and loading rate. Elastic moduli (Young's modulus and shear modulus) of the false fold tissues were calculated from the measured data. [Work supported by NIH.

  16. False recognition of instruction-set lures.

    PubMed

    Curtis, Evan T; Chubala, Chrissy M; Spear, Jackie; Jamieson, Randall K; Hockley, William E; Crump, Matthew J C

    2016-01-01

    False remembering has been examined using a variety of procedures, including the Deese-Roediger-McDermott procedure, the false fame procedure and the two-list recognition procedure. We present six experiments in a different empirical framework examining false recognition of words included in the experimental instructions (instruction-set lures). The data show that participants' false alarm rate to instruction-set lures was twice their false alarm rate to standard lures. That result was statistically robust even when (1) the relative strength of targets to instruction-set lures was increased, (2) participants were warned about the instruction-set lures, (3) the instruction-set lures were camouflaged in the study instructions and (4) the instruction-set lures were presented verbally at study but visually at test. False recognition of instruction-set lures was only mitigated when participants were distracted between encountering the instruction-set lures and studying the training list. The results confirm the ease with which recognition succumbs to familiarity and demonstrate the robustness of false recognition.

  17. Ambiguity in Tactile Apparent Motion Perception

    PubMed Central

    Liaci, Emanuela; Bach, Michael; Tebartz van Elst, Ludger; Heinrich, Sven P.; Kornmeier, Jürgen

    2016-01-01

    Background In von Schiller’s Stroboscopic Alternative Motion (SAM) stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio (“AR”, i.e. the relation between vertical and horizontal dot distances). Further, with equal horizontal and vertical dot distances (AR = 1) perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion. Methods We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants’ forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames. Results Increasing the tactile SAM’s AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias. Discussion Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual

  18. Justifying all the fuss about false belief.

    PubMed

    Russell, James

    2005-07-01

    The classic study by Wimmer and Perner showed that children below the age of about 4 years of age fail to appreciate others' false beliefs. This opened the floodgates to the theory-of-mind research programme. Recently, a study by Riggs and Simpson has called the central challenge of false belief into question, reporting similar difficulties with true belief. I would argue, however, that not only should the acquisition of false belief remain a central concern but that we should think harder about it and its earlier manifestations.

  19. 39 CFR 946.2 - Disposition of property of apparent owners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Disposition of property of apparent owners. 946.2 Section 946.2 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS...

  20. Response of Swimming Paramecia to in situ changes in their apparent weight

    NASA Astrophysics Data System (ADS)

    Jung, Ilyong; Mickalide, Harry; Valles, James M., Jr.

    2012-02-01

    There is a class of marine micro-organisms that are small enough that low Reynold's number hydrodynamics dictates their swimming mechanics and large enough that the force of gravity exerts a noticeable influence on their motion. Experiments on populations of paramecia suggest that they exert a greater propulsion when swimming against gravity. This negative gravi-kinesis is surprising because it suggests that they sense their tiny apparent weight of about 80 pN. To understand this response in more detail, we are investigating how individual paramecia caudatum change their swimming speed and helical trajectories in response to changes in their apparent weight. We vary the apparent weight with the technique of Magnetic Force Buoyancy Variation employing a high field resistive magnet at the National High Magnetic Field Laboratory. We will present analysis of the swimming for apparent weight changes as large as a factor of 8.

  1. Investigations of the Response of Swimming Paramecia to Variations in their Apparent Weight

    NASA Astrophysics Data System (ADS)

    Valles, James; Jung, Ilyong; Guevorkian, Karine; Mickalide, Harry; Wagman, Michael

    2011-11-01

    There is a set of micro-organisms that are small enough that they swim at low Reynolds number and large enough that gravity exerts an influence on their behavior Many protists, like paramecia, for example, exhibit negative gravi-taxis by orienting their swimming upward and negative gravi-kinesis by increasing their propulsion when swimming against their apparent weight. It is not clear whether these responses to a very weak force (about 100 pN) are active or passive. We have developed a technique, Magnetic Force Buoyancy Variation, which enables us to vary the apparent weight of the swimmers in situ. We will describe experiments on paramecia conducted at the National High Magnetic Field Laboratory. In particular, we will describe how increasing the apparent weight induces paramecia to accumulate at upper surfaces. A simple force model suggests that this accumulation is a passive response. Supported by NSF-PHY0750360 and a grant to the NHMFL, NSF DMR-0654118.

  2. Fenofibric Acid Can Cause False-Positive Urine Methylenedioxymethamphetamine Immunoassay Results.

    PubMed

    Quesada, Loreto; Gomila, Isabel; Fe, Antonia; Servera, Miguel A; Yates, Christopher; Morell-Garcia, Daniel; Castanyer, Bartomeu; Barceló, Bernardino

    2015-01-01

    We present a false-positive result of ecstasy (3,4-methylenedioxy-NN-methylamphetamine) screening due to the therapeutic use of fenofibrate, an antihyperlipidemic drug. Our hypothesis was that the main metabolite of fenofibrate, fenofibric acid, was responsible for this cross-reactivity on a DRI(®) Ecstasy Assay, using a cut-off of 500 ng/mL. We estimated that the addition of 225 µg/mL pure fenofibric acid to blank urine would be sufficient to result in a positive DRI(®) Ecstasy Assay. The results obtained on the urine samples analyses of the patient show that the DRI(®) Ecstasy Assay resulted negative 2 days after discontinuing fenofibrate treatment, when the urine fenofibric acid concentration corrected by creatinine and determinated by gas chromatography-mass spectrometry was 20.3 µg/mg creatinine. The cross-reactivity data for fenofibric acid would seem to indicate that there was insufficient concentration of measured compound to account for the positive immunochemical results for ecstasy. This apparent discrepancy can be explained in several ways, one of them is that the β-glucuronidase-resistent fenofibric acid isomers are responsible. This process could explain the low recovery of free fenofibric acid when we use the developed method for its quantification in urine samples. Positive results on immunoassay screening must be considered presumptive until confirmation with another method based on a different principle, preferably gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry.

  3. Visual false memories in posttraumatic stress disorder.

    PubMed

    Moradi, Ali Reza; Heydari, Ali Hosain; Abdollahi, Mohammad Hossain; Rahimi-Movaghar, Vafa; Dalgleish, Tim; Jobson, Laura

    2015-11-01

    This study investigated visual false memories in posttraumatic stress disorder (PTSD). The Scenic False Memory paradigm (SFM, Hauschildt, Peters, Jelinek, & Moritz, 2012) was administered to male Iranian military personnel who had participated in the Iran-Iraq war and were diagnosed with (n = 21) or without (n = 21) PTSD and a sample of healthy male non-trauma-exposed controls (n = 21). Trauma-exposed participants recalled and recognized a significantly lower percentage of hits and a significantly greater percentage of false memories for both trauma-related and non-trauma-related video scenes, than non-trauma-exposed controls. Among the trauma-exposed participants, those with and without PTSD did not differ significantly in terms of percentage of hits and false memories recalled on the SFM. Those with PTSD were found to recognize significantly fewer hits for both the trauma-related and non-trauma-related videos than those without PTSD. Those with PTSD also recognized significantly more false memories for the trauma video scene than the non-PTSD group. The findings suggest that those with trauma exposure, and in particular those with PTSD, may have a greater susceptibility to visual false memory.

  4. Altered perception of apparent motion in schizophrenia spectrum disorder.

    PubMed

    Tschacher, Wolfgang; Dubouloz, Priscilla; Meier, Rahel; Junghan, Uli

    2008-06-30

    Apparent motion (AM), the Gestalt perception of motion in the absence of physical motion, was used to study perceptual organization and neurocognitive binding in schizophrenia. Associations between AM perception and psychopathology as well as meaningful subgroups were sought. Circular and stroboscopic AM stimuli were presented to 68 schizophrenia spectrum patients and healthy participants. Psychopathology was measured using the Positive and Negative Syndrome Scale (PANSS). Psychopathology was related to AM perception differentially: Positive and disorganization symptoms were linked to reduced gestalt stability; negative symptoms, excitement and depression had opposite regression weights. Dimensions of psychopathology thus have opposing effects on gestalt perception. It was generally found that AM perception was closely associated with psychopathology. No difference existed between patients and controls, but two latent classes were found. Class A members who had low levels of AM stability made up the majority of inpatients and control subjects; such participants were generally young and male, with short reaction times. Class B typically contained outpatients and some control subjects; participants in class B were older and showed longer reaction times. Hence AM perceptual dysfunctions are not specific for schizophrenia, yet AM may be a promising stage marker.

  5. Apparent anisotropy in inhomogeneous isotropic media

    NASA Astrophysics Data System (ADS)

    Lin, Fan-Chi; Ritzwoller, Michael H.

    2011-09-01

    Surface waves propagating through a laterally inhomogeneous medium undergo wavefield complications such as multiple scattering, wave front healing, and backward scattering. Unless accounted for accurately, these effects will introduce a systematic isotropic bias in estimates of azimuthal anisotropy. We demonstrate with synthetic experiments that backward scattering near an observing station will introduce an apparent 360° periodicity into the azimuthal distribution of anisotropy near strong lateral variations in seismic wave speeds that increases with period. Because it violates reciprocity, this apparent 1ψ anisotropy, where ψ is the azimuthal angle, is non-physical for surface waves and is, therefore, a useful indicator of isotropic bias. Isotropic bias of the 2ψ (180° periodicity) component of azimuthal anisotropy, in contrast, is caused mainly by wave front healing, which results from the broad forward scattering part of the surface wave sensitivity kernel. To test these predictions, we apply geometrical ray theoretic (eikonal) tomography to teleseismic Rayleigh wave measurements across the Transportable Array component of USArray to measure the directional dependence of phase velocities between 30 and 80 s period. Eikonal tomography accounts for multiple scattering (ray bending) but not finite frequency effects such as wave front healing or backward scattering. At long periods (>50 s), consistent with the predictions from the synthetic experiments, a significant 1ψ component of azimuthal anisotropy is observed near strong isotropic structural contrasts with fast directions that point in the direction of increasing phase speeds. The observed 2ψ component of azimuthal anisotropy is more weakly correlated with synthetic predictions of isotropic bias, probably because of the imprint of intrinsic structural anisotropy. The observation of a 1ψ component of azimuthal anisotropy is a clear indicator of isotropic bias in the inversion caused by unmodelled

  6. Hepatitis B virus (HBV) and dual HBV-hepatitis delta virus (HDV) infection in apparently healthy persons.

    PubMed

    Brehar-Cioflec, D; Claici, C; Roşiu, N; Negrea, D A; Moldovan, R; Coşniţă, M

    1998-01-01

    The main aims of the present study were to evaluate the transfusional risk concerning HBV and HBV-HDV infections and the prevalence of viral serum markers in apparently healthy persons. Our study included 226 apparently healthy persons in whom we performed tests for HBV (HBsAg, HBsAb, HBcAb) and HDV (Delta Ab) serum markers, using the enzyme immunoassay. In 45 (19.9%) subjects we detected serum HBsAg. In the 181 HBsAg-negative apparently healthy persons, our tests detected HBsAb (31 subjects) and HBcAb (49 subjects). Thus, 125 (55.3%) of the 226 apparently healthy persons had serologic evidence of past HBV infections. Delta Ab were detected in 3 (1.3%) of our subjects. We must state that one of the three Delta Ab-positive apparently healthy persons tested negative for both HBsAg and HBcAb.

  7. False hyperlactatemia in life-threatening ethylene glycol poisoning.

    PubMed

    Riquier, T; Geri, G; Mongardon, N; Bourgogne, E; Pène, F

    2014-04-01

    Ethylene glycol poisoning is rare, but prompt diagnosis is crucial, in order to initiate specific treatments. Herein, we report the case of a patient who was admitted to ICU for coma and extreme metabolic acidosis with unexpected hyperlactatemia on initial ICU blood gas analyzer. Ethylene glycol poisoning was diagnosed, and hyperlactatemia was ruled out on a blood sample sent to the biochemistry department. Interference of blood gas analyzers lactate electrodes with metabolites of ethylene glycol were the source of this apparent hyperlactatemia. Symptoms gradually improved and false hyperlactatemia resolved after renal replacement therapy and fomepizole administration. Time course of ethylene glycol concentration showed similar evolution. After initial confirmation of ethylene glycol presence, this biological interference could thus be used as a surrogate of costly and highly specialised dosages.

  8. False-positive results with amylase testing of citrus fruits.

    PubMed

    Ricci, Ugo; Carboni, Ilaria; Torricelli, Francesca

    2014-09-01

    In a case of robbery in which the criminals passed through the garden adorned with calamondin trees (Citrus madurensis), the investigators found in the grass six calamondin fruits, some undamaged, while others apparently bitten. The fruits were collected and sent to the laboratory for DNA analysis to verify the presence of saliva and robbers' DNA profile. A specific immunochromatographic strip test for saliva confirmed the presence of human salivary α-amylase, but similar positive results were also observed for intact calamondin and other citrus fruits. Further analysis with a specific automated amylase test confirmed the absence of amylase activity. DNA quantification and typing using a specific forensic kit revealed no human DNA presence in any fruits. This case report demonstrates for the first time the occurrence of false positives when human saliva is sought on citrus fruits.

  9. Developmental trends in different types of spontaneous false memories: implications for the legal field.

    PubMed

    Otgaar, Henry; Howe, Mark L; Peters, Maarten; Sauerland, Melanie; Raymaekers, Linsey

    2013-01-01

    In an emerging area of memory research, it is becoming apparent that one particular type of false memory, called spontaneous false memory, follows a developmental trajectory that is the opposite of what is commonly assumed in false memory research - that is, spontaneous false memories are more likely to occur in adults than in children. The present study focused on developmental trends of different types of spontaneous false memories. Specifically, in the current study, 6-8 year-olds, 10-12 year-olds, and adults were presented with two methods to induce spontaneous false memories: (i) semantically related word lists that are commonly used to evoke spontaneous false memories [i.e, Deese-Roediger-McDermott (DRM) paradigm]; and (ii) a video in which related details were not shown but were presented during a recognition task. The results showed that children were more likely to form false memories than adults in the video false memory paradigm, whereas DRM false memories were more evident in adults than in children. Furthermore, we found that on a general level, DRM false memories were positively related to video spontaneous false memories. We explain that stimuli that contain obvious themes attenuate or even reverse developmental trends in spontaneous false memories.

  10. Apparent life-threatening event in infancy

    PubMed Central

    Choi, Hee Joung

    2016-01-01

    An apparent life-threatening event (ALTE) is defined as the combination of clinical presentations such as apnea, marked change in skin and muscle tone, gagging, or choking. It is a frightening event, and it predominantly occurs during infancy at a mean age of 1–3 months. The causes of ALTE are categorized into problems that are: gastrointestinal (50%), neurological (30%), respiratory (20%), cardiovascular (5%), metabolic and endocrine (2%–5%), or others such as child abuse. Up to 50% of ALTEs are idiopathic, where the cause cannot be diagnosed. Infants with an ALTE are often asymptomatic at hospital and there is no standard workup protocol for ALTE. Therefore, a detailed initial history and physical examination are important to determine the extent of the medical evaluation and treatment. Regardless of the cause of an ALTE, all infants with an ALTE should require hospitalization and continuous cardiorespiratory monitoring and evaluation for at least 24 hours. The natural course of ALTEs has seemed benign, and the outcome is generally associated with the affected infants' underlying disease. In conclusion, systemic diagnostic evaluation and adequate treatment increases the survival and quality of life for most affected infants. PMID:27721838

  11. Apparent speed increases at low luminance

    PubMed Central

    Vaziri-Pashkam, Maryam; Cavanagh, Patrick

    2009-01-01

    To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m2) to match that of a high-luminance one (1260 cd/m2). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. Next the role of motion smear in speed overestimation was examined. First it was shown that the length of the perceived motion smear increased at low luminances. Second, the length of the visible smear was manipulated by changing the presentation time of the stimuli. Speed overestimation was reduced at shorter presentation times. Third the speed of a blurred stimulus was compared to a stimulus with sharp edges and the blurred stimulus was judged to move faster. These results indicate that the length of motion smear following a target contributes to its perceived speed and that this leads to speed overestimation at low luminance where motion traces lengthen because of increased persistence. PMID:19146275

  12. Epidemiology, Public Health, and the Rhetoric of False Positives

    PubMed Central

    Blair, Aaron; Saracci, Rodolfo; Vineis, Paolo; Cocco, Pierluigi; Forastiere, Francesco; Grandjean, Philippe; Kogevinas, Manolis; Kriebel, David; McMichael, Anthony; Pearce, Neil; Porta, Miquel; Samet, Jonathan; Sandler, Dale P.; Costantini, Adele Seniori; Vainio, Harri

    2009-01-01

    Background As an observational science, epidemiology is regarded by some researchers as inherently flawed and open to false results. In a recent paper, Boffetta et al. [Boffetta P, McLaughlin JK, LaVecchia C, Tarone RE, Lipworth L, Blot WJ. False-positive results in cancer epidemiology: a plea for epistemological modesty. J Natl Cancer Inst 100:988–995 (2008)] argued that “epidemiology is particularly prone to the generation of false-positive results.” They also said “the tendency to emphasize and over-interpret what appear to be new findings is commonplace, perhaps in part because of a belief that the findings provide information that may ultimately improve public health” and that “this tendency to hype new findings increases the likelihood of downplaying inconsistencies within the data or any lack of concordance with other sources of evidence.” The authors supported these serious charges against epidemiology and epidemiologists with few examples. Although we acknowledge that false positives do occur, we view the position of Boffetta and colleagues on false positives as unbalanced and potentially harmful to public health. Objective We aim to provide a more balanced evaluation of epidemiology and its contribution to public health discourse. Discussion Boffetta and colleagues ignore the fact that false negatives may arise from the very processes that they tout as generating false-positive results. We further disagree with their proposition that false-positive results from a single study will lead to faulty decision making in matters of public health importance. In practice, such public health evaluations are based on all the data available from all relevant disciplines and never to our knowledge on a single study. Conclusions The lack of balance by Boffetta and colleagues in their evaluation of the impact of false-positive findings on epidemiology, the charge that “methodological vigilance is often absent” in epidemiologists’ interpretation of

  13. Learning words from speakers with false beliefs.

    PubMed

    Papafragou, Anna; Fairchild, Sarah; Cohen, Matthew L; Friedberg, Carlyn

    2016-06-21

    During communication, hearers try to infer the speaker's intentions to be able to understand what the speaker means. Nevertheless, whether (and how early) preschoolers track their interlocutors' mental states is still a matter of debate. Furthermore, there is disagreement about how children's ability to consult a speaker's belief in communicative contexts relates to their ability to track someone's belief in non-communicative contexts. Here, we study young children's ability to successfully acquire a word from a speaker with a false belief; we also assess the same children's success on a traditional false belief attribution task. We show that the ability to consult the epistemic state of a speaker during word learning develops between the ages of three and five. We also show that false belief understanding in word-learning contexts proceeds similarly to standard belief-attribution contexts when the tasks are equated. Our data offer evidence for the development of mind-reading abilities during language acquisition.

  14. FALSE MEMORY AND OBSESSIVE–COMPULSIVE SYMPTOMS

    PubMed Central

    Klumpp, Heide; Amir, Nader; Garfinkel, Sarah N.

    2013-01-01

    Background The memory deficit hypothesis has been used to explain the maintenance of repetitive behavior in individuals with obsessive–compulsive disorder, yet the majority of studies focusing on verbal memory show mixed results. These studies primarily evaluated memory accuracy via the inclusion or omission of previously encountered material, as opposed to false recognition (i.e., the inclusion of erroneous material). We evaluated false memories and memory processes in individuals with obsessive–compulsive washing symptoms (OC), individuals matched on depression and anxiety without OC symptoms (D/A), and in nonanxious individuals (NAC). Methods Twenty-eight OC, 28 D/A, and 29 NAC individuals read OC-threat relevant, positive, and neutral scenarios and then performed a recognition test. Erroneous recognition of words associated to encoded, but not previously viewed, scenarios were classified as false memories. To evaluate processes underlying memory, participants completed a modified remember/know task to examine whether the OC individuals differed from the other individuals in recollective clarity for false memories of OC-relevant (e.g., germs), positive (e.g., lottery), and neutral (e.g., bread) material. Results The OC individuals used “know” more than the D/A and NAC individuals for false memories of threat. For veridical memories, the OC individuals used “know” more than the NAC, but not, D/A individuals. Conclusions The greater reliance on “know” (i.e., feelings of familiarity) in general and false threat memories in particular in individuals with OC symptoms may add to feelings of uncertainty for threat-relevant material, which may contribute to compulsive behavior. PMID:18839404

  15. Apparent diffusion coefficient of normal adrenal glands*

    PubMed Central

    Teixeira, Sara Reis; Elias, Paula Condé Lamparelli; Leite, Andrea Farias de Melo; de Oliveira, Tatiane Mendes Gonçalves; Muglia, Valdair Francisco; Elias Junior, Jorge

    2016-01-01

    Objective To assess the feasibility and reliability of apparent diffusion coefficient (ADC) measurements of normal adrenal glands. Materials and methods This was a retrospective study involving 32 healthy subjects, divided into two groups: prepubertal (PreP, n = 12), aged from 2 months to 12.5 years (4 males; 8 females); and postpubertal (PostP, n = 20), aged from 11.9 to 61 years (5 males; 15 females). Diffusion-weighted magnetic resonance imaging (DW-MRI) sequences were acquired at a 1.5 T scanner using b values of 0, 20, 500, and 1000 s/mm2. Two radiologists evaluated the images. ADC values were measured pixel-by-pixel on DW-MRI scans, and automatic co-registration with the ADC map was obtained. Results Mean ADC values for the right adrenal glands were 1.44 × 10-3 mm2/s for the PreP group and 1.23 × 10-3 mm2/s for the PostP group, whereas they were 1.58 × 10-3 mm2/s and 1.32 × 10-3 mm2/s, respectively, for the left glands. ADC values were higher in the PreP group than in the PostP group (p < 0.05). Agreement between readers was almost perfect (intraclass correlation coefficient, 0.84-0.94; p < 0.05). Conclusion Our results demonstrate the feasibility and reliability of performing DW-MRI measurements of normal adrenal glands. They could also support the feasibility of ADC measurements of small structures. PMID:28057963

  16. Apparent exchange rate for breast cancer characterization.

    PubMed

    Lasič, Samo; Oredsson, Stina; Partridge, Savannah C; Saal, Lao H; Topgaard, Daniel; Nilsson, Markus; Bryskhe, Karin

    2016-05-01

    Although diffusion MRI has shown promise for the characterization of breast cancer, it has low specificity to malignant subtypes. Higher specificity might be achieved if the effects of cell morphology and molecular exchange across cell membranes could be disentangled. The quantification of exchange might thus allow the differentiation of different types of breast cancer cells. Based on differences in diffusion rates between the intra- and extracellular compartments, filter exchange spectroscopy/imaging (FEXSY/FEXI) provides non-invasive quantification of the apparent exchange rate (AXR) of water between the two compartments. To test the feasibility of FEXSY for the differentiation of different breast cancer cells, we performed experiments on several breast epithelial cell lines in vitro. Furthermore, we performed the first in vivo FEXI measurement of water exchange in human breast. In cell suspensions, pulsed gradient spin-echo experiments with large b values and variable pulse duration allow the characterization of the intracellular compartment, whereas FEXSY provides a quantification of AXR. These experiments are very sensitive to the physiological state of cells and can be used to establish reliable protocols for the culture and harvesting of cells. Our results suggest that different breast cancer subtypes can be distinguished on the basis of their AXR values in cell suspensions. Time-resolved measurements allow the monitoring of the physiological state of cells in suspensions over the time-scale of hours, and reveal an abrupt disintegration of the intracellular compartment. In vivo, exchange can be detected in a tumor, whereas, in normal tissue, the exchange rate is outside the range experimentally accessible for FEXI. At present, low signal-to-noise ratio and limited scan time allows the quantification of AXR only in a region of interest of relatively large tumors.

  17. Infants' Reasoning about Others' False Perceptions

    ERIC Educational Resources Information Center

    Song, Hyun-joo; Baillargeon, Renee

    2008-01-01

    Prior research suggests that children younger than age 3 or 4 do not understand that an agent may be deceived by an object's misleading appearance. The authors asked whether 14.5-month-olds would give evidence in a violation-of-expectation task that they understand that agents may form false perceptions. Infants first watched events in which an…

  18. Development of the False-Memory Illusion

    ERIC Educational Resources Information Center

    Brainerd, C. J.; Forrest, T. J.; Karibian, D.; Reyna, V. F.

    2006-01-01

    The counterintuitive developmental trend in the Deese-Roediger-McDermott (DRM) illusion (that false-memory responses increase with age) was investigated in learning-disabled and nondisabled children from the 6- to 14-year-old age range. Fuzzy-trace theory predicts that because there are qualitative differences in how younger versus older children…

  19. False Accusations of Nosocomial Sexual Abuse.

    ERIC Educational Resources Information Center

    Money, John

    1992-01-01

    Practitioners performing routine physical examination may be falsely accused of sexual abuse. Criminal justice system is incompatible with biomedical system of prevention. It is responsible for establishment of sexual abuse industry, practitioners of which have vested interest in maintaining status quo of sexual criminalization. They themselves…

  20. Vendor cited for false PFC savings claim

    SciTech Connect

    Greenstein, I.

    1983-08-29

    A Cynex power factor controller (PFC) vendor claiming a 60% saving was cited by the Better Business Bureau for false advertising after a user survey revealed that savings were only 20% at best. The company plans no future advertising claims, although it insists that 60% savings are possible. The inventor disagrees. (DCK)

  1. How to Justify Teaching False Science

    ERIC Educational Resources Information Center

    Slater, Matthew H.

    2008-01-01

    We often knowingly teach false science. Such a practice conflicts with a prima facie pedagogical value placed on teaching only what is true. I argue that only a partial dissolution of the conflict is possible: the proper aim of instruction in science is not to provide an armory of facts about what things the world contains, how they interact, and…

  2. Analysis of False Starts in Spontaneous Speech.

    ERIC Educational Resources Information Center

    O'Shaughnessy, Douglas

    A primary difference between spontaneous speech and read speech concerns the use of false starts, where a speaker interrupts the flow of speech to restart his or her utterance. A study examined the acoustic aspects of such restarts in a widely-used speech database, examining approximately 1000 utterances, about 10% of which contained a restart.…

  3. A Synchronization Account of False Recognition

    ERIC Educational Resources Information Center

    Johns, Brendan T.; Jones, Michael N.; Mewhort, Douglas J. K.

    2012-01-01

    We describe a computational model to explain a variety of results in both standard and false recognition. A key attribute of the model is that it uses plausible semantic representations for words, built through exposure to a linguistic corpus. A study list is encoded in the model as a gist trace, similar to the proposal of fuzzy trace theory…

  4. False positive reduction for lung nodule CAD

    NASA Astrophysics Data System (ADS)

    Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.

    2007-03-01

    Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.

  5. False alarm reduction in critical care.

    PubMed

    Clifford, Gari D; Silva, Ikaro; Moody, Benjamin; Li, Qiao; Kella, Danesh; Chahin, Abdullah; Kooistra, Tristan; Perry, Diane; Mark, Roger G

    2016-08-01

    High false alarm rates in the ICU decrease quality of care by slowing staff response times while increasing patient delirium through noise pollution. The 2015 PhysioNet/Computing in Cardiology Challenge provides a set of 1250 multi-parameter ICU data segments associated with critical arrhythmia alarms, and challenges the general research community to address the issue of false alarm suppression using all available signals. Each data segment was 5 minutes long (for real time analysis), ending at the time of the alarm. For retrospective analysis, we provided a further 30 seconds of data after the alarm was triggered. A total of 750 data segments were made available for training and 500 were held back for testing. Each alarm was reviewed by expert annotators, at least two of whom agreed that the alarm was either true or false. Challenge participants were invited to submit a complete, working algorithm to distinguish true from false alarms, and received a score based on their program's performance on the hidden test set. This score was based on the percentage of alarms correct, but with a penalty that weights the suppression of true alarms five times more heavily than acceptance of false alarms. We provided three example entries based on well-known, open source signal processing algorithms, to serve as a basis for comparison and as a starting point for participants to develop their own code. A total of 38 teams submitted a total of 215 entries in this year's Challenge. This editorial reviews the background issues for this challenge, the design of the challenge itself, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. Additionally we make some recommendations for future changes in the field of patient monitoring as a result of the Challenge.

  6. Emotional false memories in children with learning disabilities.

    PubMed

    Mirandola, Chiara; Losito, Nunzia; Ghetti, Simona; Cornoldi, Cesare

    2014-02-01

    Research has shown that children with learning disabilities (LD) are less prone to evince associative illusions of memory as a result of impairments in their ability to engage in semantic processing. However, it is unclear whether this observation is true for scripted life events, especially if they include emotional content, or across a broad spectrum of learning disabilities. The present study addressed these issues by assessing recognition memory for script-like information in children with nonverbal learning disability (NLD), children with dyslexia, and typically developing children (N=51). Participants viewed photographs about 8 common events (e.g., family dinner), and embedded in each episode was either a negative or a neutral consequence of an unseen action. Children's memory was then tested on a yes/no recognition task that included old and new photographs. Results showed that the three groups performed similarly in recognizing target photographs, but exhibited differences in memory errors. Compared to other groups, children with NLD were more likely to falsely recognize photographs that depicted an unseen cause of an emotional seen event and associated more "Remember" responses to these errors. Children with dyslexia were equally likely to falsely recognize both unseen causes of seen photographs and photographs generally consistent with the script, whereas the other participant groups were more likely to falsely recognize unseen causes rather than script-consistent distractors. Results are interpreted in terms of mechanisms underlying false memories' formation in different clinical populations of children with LD.

  7. Reducing False Positives in Runtime Analysis of Deadlocks

    NASA Technical Reports Server (NTRS)

    Bensalem, Saddek; Havelund, Klaus; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This paper presents an improvement of a standard algorithm for detecting dead-lock potentials in multi-threaded programs, in that it reduces the number of false positives. The standard algorithm works as follows. The multi-threaded program under observation is executed, while lock and unlock events are observed. A graph of locks is built, with edges between locks symbolizing locking orders. Any cycle in the graph signifies a potential for a deadlock. The typical standard example is the group of dining philosophers sharing forks. The algorithm is interesting because it can catch deadlock potentials even though no deadlocks occur in the examined trace, and at the same time it scales very well in contrast t o more formal approaches to deadlock detection. The algorithm, however, can yield false positives (as well as false negatives). The extension of the algorithm described in this paper reduces the amount of false positives for three particular cases: when a gate lock protects a cycle, when a single thread introduces a cycle, and when the code segments in different threads that cause the cycle can actually not execute in parallel. The paper formalizes a theory for dynamic deadlock detection and compares it to model checking and static analysis techniques. It furthermore describes an implementation for analyzing Java programs and its application to two case studies: a planetary rover and a space craft altitude control system.

  8. Accounting for Slipping and Other False Negatives in Logistic Models of Student Learning

    ERIC Educational Resources Information Center

    MacLellan, Christopher J.; Liu, Ran; Koedinger, Kenneth R.

    2015-01-01

    Additive Factors Model (AFM) and Performance Factors Analysis (PFA) are two popular models of student learning that employ logistic regression to estimate parameters and predict performance. This is in contrast to Bayesian Knowledge Tracing (BKT) which uses a Hidden Markov Model formalism. While all three models tend to make similar predictions,…

  9. Reducing False Negative Reads in RFID Data Streams Using an Adaptive Sliding-Window Approach

    PubMed Central

    Massawe, Libe Valentine; Kinyua, Johnson D. M.; Vermaak, Herman

    2012-01-01

    Unreliability of the data streams generated by RFID readers is among the primary factors which limit the widespread adoption of the RFID technology. RFID data cleaning is, therefore, an essential task in the RFID middleware systems in order to reduce reading errors, and to allow these data streams to be used to make a correct interpretation and analysis of the physical world they are representing. In this paper we propose an adaptive sliding-window based approach called WSTD which is capable of efficiently coping with both environmental variation and tag dynamics. Our experimental results demonstrate the efficacy of the proposed approach. PMID:22666027

  10. True versus False Positives and Negatives on the "Modified Checklist for Autism in Toddlers"

    ERIC Educational Resources Information Center

    Matson, Johnny L.; Kozlowski, Alison M.; Fitzgerald, Mary E.; Sipes, Megan

    2013-01-01

    Given the importance of early intervention services for children with autism spectrum disorders (ASD), early diagnosis of children is critical. At present, several ASD screeners exist for young children, with the "Modified Checklist for Autism in Toddlers" ("M-CHAT") being one of the most widely researched. While the "M-CHAT" has good sensitivity…

  11. Indium-111 leukocyte scanning. False-negative study in a renal abscess

    SciTech Connect

    Kumar, R.; Bedi, D.G.; Fawcett, H.D.; Winsett, M.Z.; Fagan, C.J.

    1986-04-01

    A 33-year-old man had clinical features of a right renal abscess. Results of excretory urography and ultrasonography showed a focal complex mass lesion in the right kidney. An In-111 leukocyte scan failed to detect the right renal abscess, which later was aspirated under CT guidance and explored surgically. The role of In-111 leukocyte imaging in the detection of intra-abdominal abscesses, with limitations of the procedure, is discussed.

  12. Multiple Choice and True/False Tests: Reliability Measures and Some Implications of Negative Marking

    ERIC Educational Resources Information Center

    Burton, Richard F.

    2004-01-01

    The standard error of measurement usefully provides confidence limits for scores in a given test, but is it possible to quantify the reliability of a test with just a single number that allows comparison of tests of different format? Reliability coefficients do not do this, being dependent on the spread of examinee attainment. Better in this…

  13. Falsely Negative F-18 FDG PET of Osteosarcoma Arising In Paget Disease.

    PubMed

    Bush, Lisabeth Ann; Toresdahl, Brett; Hoch, Benjamin; Chew, Felix S

    2009-01-01

    We present the case of a large, painful pelvic bone tumor in a 53-year-old woman with severe Paget disease. Her presentation was complicated with bilateral total hip arthroplasty, history of spinal stenosis, and multiple lucent lesions in the spine and pelvis in severely affected pagetoid bone. This case features the rare but dreaded complication of osteosarcomatous transformation in Paget disease. A variety of imaging modalities including PET/CT were utilized in the evaluation of these lesions. The PET/CT findings were counter-intuitive with regard to the intense uptake of the underlying chronic disease process and the near-absence of uptake in the tumors. The histology of the pelvic mass is also intriguing, as it demonstrated a sarcoma with giant cell features. Conservative, non-operative management was chosen, due to the patient's poor medical condition, so we may never know the nature of the spinal lesion in this case, but will discuss the differential diagnosis for a lytic spinal lesion in a patient with severe Paget disease complicated by osteosarcoma with giant cell features.

  14. Strictly Subversive: Films of False Liberation.

    ERIC Educational Resources Information Center

    Resnick, David

    1996-01-01

    Examines two recent films--"Scent of a Woman" and "Strictly Ballroom"--that project stereotypical negative portrayals of educational institutions and their limited capacity for reform. Both films bring their audiences to view educational institutions as worthy of destruction and, by focusing on "quick fixes," fail to address the difficulties of…

  15. Apparent diffusion coefficient normalization of normal liver

    PubMed Central

    Zhu, Jie; Zhang, Jie; Gao, Jia-Yin; Li, Jin-Ning; Yang, Da-Wei; Chen, Min; Zhou, Cheng; Yang, Zheng-Han

    2017-01-01

    Abstract Apparent diffusion coefficient (ADC) measurement in diffusion-weighted imaging (DWI) has been reported to be a helpful biomarker for detection and characterization of lesion. In view of the importance of ADC measurement reproducibility, the aim of this study was to probe the variability of the healthy hepatic ADC values measured at 3 MR scanners from different vendors and with different field strengths, and to investigate the reproducibility of normalized ADC (nADC) value with the spleen as the reference organ. Thirty enrolled healthy volunteers received DWI with GE 1.5T, Siemens 1.5T, and Philips 3.0T magnetic resonance (MR) systems on liver and spleen (session 1) and were imaged again after 10 to 14 days using only GE 1.5T MR and Philips 3.0T MR systems (session 2). Interscan agreement and reproducibility of ADC measurements of liver and the calculated nADC values (ADCliver/ADCspleen) were statistically evaluated between 2 sessions. In session 1, ADC and nADC values of liver were evaluated for the scanner-related variability by 2-way analysis of variance and intraclass correlation coefficients (ICCs). Coefficients of variation (CVs) of ADCs and nADCs of liver were calculated for both 1.5 and 3.0-T MR system. Interscan agreement and reproducibility of ADC measurements of liver and related nADCs between 2 sessions were found to be satisfactory with ICC values of 0.773 to 0.905. In session 1, the liver nADCs obtained from different scanners were consistent (P = 0.112) without any significant difference in multiple comparison (P = 0.117 to >0.99) by using 2-way analysis of variance with post-hoc analysis of Bonferroni method, although the liver ADCs varied significantly (P < 0.001). nADCs measured by 3 scanners were in good interscanner agreements with ICCs of 0.685 to 0.776. The mean CV of nADCs of both 1.5T MR scanners (9.6%) was similar to that of 3.0T MR scanner (8.9%). ADCs measured at 3 MR scanners with different field strengths and vendors

  16. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... the bid intended. Examples of apparent mistakes are— (1) Obvious misplacement of a decimal point;...

  17. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... the bid intended. Examples of apparent mistakes are— (1) Obvious misplacement of a decimal point;...

  18. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... the bid intended. Examples of apparent mistakes are— (1) Obvious misplacement of a decimal point;...

  19. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... the bid intended. Examples of apparent mistakes are— (1) Obvious misplacement of a decimal point;...

  20. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... the bid intended. Examples of apparent mistakes are— (1) Obvious misplacement of a decimal point;...

  1. The problem with false vacuum Higgs inflation

    NASA Astrophysics Data System (ADS)

    Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert

    2014-06-01

    We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios.

  2. Cosmic chirality both true and false.

    PubMed

    Barron, Laurence D

    2012-12-01

    The discrete symmetries of parity P, time reversal T, and charge conjugation C may be used to characterize the properties of chiral systems. It is well known that parity violation infiltrates into ordinary matter via an interaction between the nucleons and electrons, mediated by the Z(0) particle, that lifts the degeneracy of the mirror-image enantiomers of a chiral molecule. Being odd under P but even under T, this P-violating interaction exhibits true chirality and so may induce absolute enantioselection under all circumstances. It has been suggested that CP violation may also infiltrate into ordinary matter via a P-odd, T-odd interaction mediated by the (as yet undetected) axion. This CP-violating interaction exhibits false chirality and so may induce absolute enantioselection in processes far from equilibrium. Both true and false cosmic chirality should be considered together as possible sources of homochirality in the molecules of life.

  3. Spirit Beholds Bumpy Boulder (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of 'Low Ridge.' The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

    Spirit took this false-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006). This image is a false-color rendering using camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

  4. Constrained potential method for false vacuum decays

    SciTech Connect

    Park, Jae-hyeon

    2011-02-01

    A procedure is reported for numerical analysis of false vacuum transition in a model with multiple scalar fields. It is a refined version of the approach by Konstandin and Huber. The alteration makes it possible to tackle a class of problems that was difficult or unsolvable with the original method, i.e. those with a distant or nonexistent true vacuum. An example with an unbounded-from-below direction is presented.

  5. False Context Fear Memory in Rats

    ERIC Educational Resources Information Center

    Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

    2015-01-01

    Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

  6. False memories in Lewy-body disease.

    PubMed

    Algarabel, Salvador; Pitarque, Alfonso; Sales, Alicia; Meléndez, Juan Carlos; Escudero, Joaquín

    2015-12-01

    Recently, de Boysson, Belleville, Phillips et al. (2011) found that patients with Lewy-body disease (LBD) showed significantly lower rates of false memories than healthy controls, using the Deese-Roediger-McDermott (DRM) experimental procedure. Given that this result could be explained by the practically null rate of true recognition in the LBD group (0.09), we decided to replicate the study by de Boysson et al. (2011), but including a new condition that would maximize the true recognition rate (and analyze its effect on the rate of false memories). Specifically, in a DRM experiment, we manipulated (within subjects) two study and recognition conditions: in the "immediate" condition, both the LBD patients and the control group of healthy older people received a different recognition test after each study list (containing twelve words associated with a non-presented critical word), while in the "delayed" condition (similar to the one in de Boysson et al., 2011), the participants received the entire series of study lists and then took only one recognition test. The results showed that, in both samples, the "immediate" condition produced higher corrected rates of both true and false recognition than the "delayed" condition, although they were both lower in the LBD patients, which shows that these patients are capable of encoding and recognizing the general similitude underlying information (gist memory) in the right conditions.

  7. Infants’ Reasoning About Others’ False Perceptions

    PubMed Central

    Song, Hyun-joo; Baillargeon, Renée

    2012-01-01

    Prior research suggests that children younger than age 3 or 4 do not understand that an agent may be deceived by an object’s misleading appearance. The authors asked whether 14.5-month-olds would give evidence in a violation-of-expectation task that they understand that agents may form false perceptions. Infants first watched events in which an agent faced a stuffed skunk and a doll with blue pigtails; the agent consistently reached for the doll, suggesting that she preferred it over the skunk. Next, while the agent was absent, the doll was hidden in a plain box, and the skunk was hidden in a box with a tuft of blue hair protruding from under its lid. Infants expected the agent to be misled by the tuft’s resemblance to the doll’s hair and to falsely perceive it as belonging to the doll. These and other results indicate that 14.5-month-old infants can already reason about agents’ false perceptions. PMID:18999340

  8. False Beliefs in Unreliable Knowledge Networks

    NASA Astrophysics Data System (ADS)

    Ioannidis, Evangelos; Varsakelis, Nikos; Antoniou, Ioannis

    2017-03-01

    The aims of this work are: (1) to extend knowledge dynamics analysis in order to assess the influence of false beliefs and unreliable communication channels, (2) to investigate the impact of selection rule-policy for knowledge acquisition, (3) to investigate the impact of targeted link attacks ("breaks" or "infections") of certain "healthy" communication channels. We examine the knowledge dynamics analytically, as well as by simulations on both artificial and real organizational knowledge networks. The main findings are: (1) False beliefs have no significant influence on knowledge dynamics, while unreliable communication channels result in non-monotonic knowledge updates ("wild" knowledge fluctuations may appear) and in significant elongation of knowledge attainment. Moreover, false beliefs may emerge during knowledge evolution, due to the presence of unreliable communication channels, even if they were not present initially, (2) Changing the selection rule-policy, by raising the awareness of agents to avoid the selection of unreliable communication channels, results in monotonic knowledge upgrade and in faster knowledge attainment, (3) "Infecting" links is more harmful than "breaking" links, due to "wild" knowledge fluctuations and due to the elongation of knowledge attainment. Moreover, attacking even a "small" percentage of links (≤5%) with high knowledge transfer, may result in dramatic elongation of knowledge attainment (over 100%), as well as in delays of the onset of knowledge attainment. Hence, links of high knowledge transfer should be protected, because in Information Warfare and Disinformation, these links are the "best targets".

  9. 40 CFR 62.06 - Negative declarations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Negative declarations. 62.06 Section 62....06 Negative declarations. A State may submit to the Administrator a letter certifying that no designated facilities exist in the State if such is the case. The negative declaration will be in lieu of...

  10. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  11. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  12. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  13. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  14. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  15. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    DOE PAGES

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; ...

    2014-12-08

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content.more » This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.« less

  16. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    SciTech Connect

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; Rodhe, Henning

    2014-12-08

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.

  17. Uranus in True and False Color

    NASA Technical Reports Server (NTRS)

    1986-01-01

    These two pictures of Uranus -- one in true color (left) and the other in false color -- were compiled from images returned Jan. 17, 1986, by the narrow-angle camera of Voyager 2. The spacecraft was 9.1 million kilometers (5.7 million miles) from the planet, several days from closest approach. The picture at left has been processed to show Uranus as human eyes would see it from the vantage point of the spacecraft. The picture is a composite of images taken through blue, green and orange filters. The darker shadings at the upper right of the disk correspond to the day-night boundary on the planet. Beyond this boundary lies the hidden northern hemisphere of Uranus, which currently remains in total darkness as the planet rotates. The blue-green color results from the absorption of red light by methane gas in Uranus' deep, cold and remarkably clear atmosphere. The picture at right uses false color and extreme contrast enhancement to bring out subtle details in the polar region of Uranus. Images obtained through ultraviolet, violet and orange filters were respectively converted to the same blue, green and red colors used to produce the picture at left. The very slight contrasts visible in true color are greatly exaggerated here. In this false-color picture, Uranus reveals a dark polar hood surrounded by a series of progressively lighter concentric bands. One possible explanation is that a brownish haze or smog, concentrated over the pole, is arranged into bands by zonal motions of the upper atmosphere. The bright orange and yellow strip at the lower edge of the planet's limb is an artifact of the image enhancement. In fact, the limb is dark and uniform in color around the planet. The Voyager project is manages for NASA by the Jet Propulsion Laboratory.

  18. False discovery rates in spectral identification.

    PubMed

    Jeong, Kyowon; Kim, Sangtae; Bandeira, Nuno

    2012-01-01

    Automated database search engines are one of the fundamental engines of high-throughput proteomics enabling daily identifications of hundreds of thousands of peptides and proteins from tandem mass (MS/MS) spectrometry data. Nevertheless, this automation also makes it humanly impossible to manually validate the vast lists of resulting identifications from such high-throughput searches. This challenge is usually addressed by using a Target-Decoy Approach (TDA) to impose an empirical False Discovery Rate (FDR) at a pre-determined threshold x% with the expectation that at most x% of the returned identifications would be false positives. But despite the fundamental importance of FDR estimates in ensuring the utility of large lists of identifications, there is surprisingly little consensus on exactly how TDA should be applied to minimize the chances of biased FDR estimates. In fact, since less rigorous TDA/FDR estimates tend to result in more identifications (at higher 'true' FDR), there is often little incentive to enforce strict TDA/FDR procedures in studies where the major metric of success is the size of the list of identifications and there are no follow up studies imposing hard cost constraints on the number of reported false positives. Here we address the problem of the accuracy of TDA estimates of empirical FDR. Using MS/MS spectra from samples where we were able to define a factual FDR estimator of 'true' FDR we evaluate several popular variants of the TDA procedure in a variety of database search contexts. We show that the fraction of false identifications can sometimes be over 10× higher than reported and may be unavoidably high for certain types of searches. In addition, we further report that the two-pass search strategy seems the most promising database search strategy. While unavoidably constrained by the particulars of any specific evaluation dataset, our observations support a series of recommendations towards maximizing the number of resulting

  19. Valence, Implicated Actor, and Children’s Acquiescence to False Suggestions

    PubMed Central

    Cleveland, Kyndra C.; Quas, Jodi A.; Lyon, Thomas D.

    2016-01-01

    Although adverse effects of suggestive interviewing on children’s accuracy are well documented, it remains unclear as to whether these effects vary depending on the valence of and the actor implicated in suggestions. In this study, 124 3-8-year-olds participated in a classroom activity and were later questioned about positive and negative false details. The interviewer provided positive reinforcement when children acquiesced to suggestions and negative feedback when they did not. Following reinforcement or feedback, young children were comparably suggestible for positive and negative details. With age, resistance to suggestions about negative details emerged first, followed by resistance to suggestions about positive details. Across age, more negative feedback was required to induce acquiescence to negative than positive false details. Finally, children were less willing to acquiesce when they (versus the confederate) were implicated. Findings highlight the interactive effects of valence and children’s age on their eyewitness performance in suggestive contexts. PMID:26955204

  20. MTS in false positive reduction for multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Cudney, Elizabeth

    2014-05-01

    The Mahalanobis Taguchi System (MTS) is a relatively new tool in the vehicle health maintenance domain, but has some distinct advantages in current multi-sensor implementations. The use of Mahalanobis Spaces (MS) allows the algorithm to identify characteristics of sensor signals to identify behaviors in machines. MTS is extremely powerful with the caveat that the correct variables are selected to form the MS. In this research work, 56 sensors monitor various aspects of the vehicles. Typically, using the MTS process, identification of useful variables is preceded by validation of the measurements scale. However, the MTS approach doesn't directly include any mitigating steps should the measurement scale not be validated. Existing work has performed outlier removal in construction of the MS, which can lead to better validation. In our approach, we modify the outlier removal process with more liberal definitions of outliers to better identify variables' impact prior to identification of useful variables. This subtle change substantially lowered the false positive rate due to the fact that additional variables were retained. Traditional MTS approaches identify useful variables only to the extent they provide usefulness in identifying the positive (abnormal) condition. The impact of removing false negatives is not included. Initial results show our approach can reduce false positive values while still maintaining complete fault identification for this vehicle data set.

  1. False alarm reduction during landmine detection

    NASA Astrophysics Data System (ADS)

    Prado, P. J.; Chongpison, A.; Doraisamy, L.

    2007-04-01

    Quadrupole Resonance sensors have the unique capability of detecting explosives from buried, plastic-cased antipersonnel and antitank landmines. The chemical specificity of this radio-frequency technique provides the potential to deliver remarkably low false alarm rates during landmine detection. This is of particular importance to deminers, who frequently come across numerous clutter items before uncovering a mine. Quadrupole Resonance is typically utilized in a confirmation mode; preceded by rapid primary scans carried out by, for example, metal detectors, ground penetrating radars or a fusion of these. Significant technical and scientific advances have resulted in the fabrication of handheld and vehicle mounted Quadrupole Resonance landmine detectors in compact, power-efficient configurations. The development work is focused on baseline sensitivity increase, as well as the achievement of high detection performance under field conditions. The mine detection capability of Quadrupole Resonance detectors has been evaluated during various blind tests. A modular handheld unit, combining primary and confirmation sensors, was designed to be operated by a single person. A series of field tests demonstrate the unique capability of Quadrupole Resonance for significant false alarm reduction.

  2. Apparent cooperativity and apparent hyperbolic behavior of enzyme mixtures acting on the same substrate.

    PubMed

    Cappiello, Mario; Balestri, Francesco; Moschini, Roberta; Del-Corso, Antonella; Mura, Umberto

    2016-12-01

    It is well known that a negative cooperative behavior displayed by a monomeric enzyme may be associated with the simultaneous presence of two enzymes acting on the same substrate. In this paper, emphasis is given to the effect exerted by a rapid equilibrium between the enzyme forms in leading to a hyperbolic behavior, thus masking the presence of multiple enzyme forms.

  3. Psychoactive drugs and false memory: comparison of dextroamphetamine and delta-9-tetrahydrocannabinol on false recognition

    PubMed Central

    Ballard, Michael E.; Gallo, David A.; de Wit, Harriet

    2014-01-01

    Rationale Several psychoactive drugs are known to influence episodic memory. However, these drugs’ effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood. Objectives Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Δ9-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger–McDermott (DRM) illusion. Methods Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions. Results As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs’ effects on true memory were positively correlated with their effects on false memory. Conclusions Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories. PMID:21647577

  4. Two Holes in 'Wooly Patch' (False Color)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The rock abrasion tool on NASA's Mars Exploration Rover Spirit ground two holes in a relatively soft rock called 'Wooly Patch' near the base of the 'Columbia Hills' inside Gusev Crater on Mars. This false-color image from the panoramic camera was taken on sol 200 (July 25, 2004) and generated using the camera's 750-, 530-, and 430-nanometer filters. It highlights the material ground up by the rock abrasion tool, grayish-blue in appearance in this image. The color of the material excavated suggests the interior of the rock contains iron minerals that are less oxidized than the dust or possibly weathered coating on the exterior of the rock. Scientists speculate that this relatively soft rock (compared to others analyzed by Spirit) may have been modified by water. Small cracks in the surface outside the drill holes may be the result of interactions with water-rich fluids.

  5. Remembering, imagining, false memories & personal meanings.

    PubMed

    Conway, Martin A; Loveday, Catherine

    2015-05-01

    The Self-Memory System encompasses the working self, autobiographical memory and episodic memory. Specific autobiographical memories are patterns of activation over knowledge structures in autobiographical and episodic memory brought about by the activating effect of cues. The working self can elaborate cues based on the knowledge they initially activate and so control the construction of memories of the past and the future. It is proposed that such construction takes place in the remembering-imagining system - a window of highly accessible recent memories and simulations of near future events. How this malfunctions in various disorders is considered as are the implication of what we term the modern view of human memory for notions of memory accuracy. We show how all memories are to some degree false and that the main role of memories lies in generating personal meanings.

  6. Controlling the false discoveries in LASSO.

    PubMed

    Huang, Hanwen

    2017-02-09

    The LASSO method estimates coefficients by minimizing the residual sum of squares plus a penalty term. The regularization parameter λ in LASSO controls the trade-off between data fitting and sparsity. We derive relationship between λ and the false discovery proportion (FDP) of LASSO estimator and show how to select λ so as to achieve a desired FDP. Our estimation is based on the asymptotic distribution of LASSO estimator in the limit of both sample size and dimension going to infinity with fixed ratio. We use a factor analysis model to describe the dependence structure of the design matrix. An efficient majorization-minimization based algorithm is developed to estimate the FDP at fixed value of λ. The analytic results are compared with those of numerical simulations on finite-size systems and are confirmed to be correct. An application to the high-throughput genomic riboavin data set also demonstrates the usefulness of our method.

  7. Opportunity View of 'Gilbert' Layer (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This view from NASA's Mars Exploration Rover Opportunity shows bedock within a stratigraphic layer informally named 'Gilbert,' which is the rover's next target after completing an examination of three stratigtaphic layers forming a bright band around the inside of Victoria Crater. The rover will descend deeper into the crater to reach the Gilbert layer.

    Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:30 p.m. during the rover's 1,429th Martian day, of sol (Jan. 31, 2008).

    This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

  8. Opportunity View of 'Lyell' Layer (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This view from NASA's Mars Exploration Rover Opportunity shows bedrock within a stratigraphic layer informally named 'Lyell,' which is the lowermost of three layers the rover has examined at a bright band around the inside of Victoria Crater.

    Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:21 p.m. during the rover's 1,433rd Martian day, of sol (Feb. 4, 2008).

    This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

  9. View from Spirit's Overwintering Position (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Mars Exploration Rover Spirit has this view northward from the position at the north edge of the 'Home Plate' plateau where the rover will spend its third Martian winter.

    Husband Hill is on the horizon. The dark area in the middle distance is 'El Dorado' sand dune field.

    Spirit used its panoramic camera (Pancam) to capture this image during the rover's 1,448th Martian day, of sol (Jan. 29, 2008).

    This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

  10. Spirit Scans Winter Haven (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand.

    This view is a false-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

  11. Apparent lethal concentrations of pyrolysis products of some polymeric materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Marcussen, W. H.; Furst, A.; Kourtides, D. A.; Parker, J. A.

    1976-01-01

    Thirty-nine samples of polymeric materials were evaluated to determine the apparent lethal concentrations of their pyrolysis products. The materials were compared on the basis of the apparent lethal concentration for 50 percent of the test animals. Relative toxicity rankings based o apparent lethal concentration values can differ significantly depending on whether they are based on weight of sample charged or weight of sample pyrolyzed. The ranking of polyphenylene sulfide is particularly sensitive to this difference.

  12. Adaptive false memory: Imagining future scenarios increases false memories in the DRM paradigm.

    PubMed

    Dewhurst, Stephen A; Anderson, Rachel J; Grace, Lydia; van Esch, Lotte

    2016-10-01

    Previous research has shown that rating words for their relevance to a future scenario enhances memory for those words. The current study investigated the effect of future thinking on false memory using the Deese/Roediger-McDermott (DRM) procedure. In Experiment 1, participants rated words from 6 DRM lists for relevance to a past or future event (with or without planning) or in terms of pleasantness. In a surprise recall test, levels of correct recall did not vary between the rating tasks, but the future rating conditions led to significantly higher levels of false recall than the past and pleasantness conditions did. Experiment 2 found that future rating led to higher levels of false recognition than did past and pleasantness ratings but did not affect correct recognition. The effect in false recognition was, however, eliminated when DRM items were presented in random order. Participants in Experiment 3 were presented with both DRM lists and lists of unrelated words. Future rating increased levels of false recognition for DRM lures but did not affect correct recognition for DRM or unrelated lists. The findings are discussed in terms of the view that false memories can be associated with adaptive memory functions.

  13. False discovery rates: a new deal

    PubMed Central

    2017-01-01

    Summary We introduce a new Empirical Bayes approach for large-scale hypothesis testing, including estimating false discovery rates (FDRs), and effect sizes. This approach has two key differences from existing approaches to FDR analysis. First, it assumes that the distribution of the actual (unobserved) effects is unimodal, with a mode at 0. This “unimodal assumption” (UA), although natural in many contexts, is not usually incorporated into standard FDR analysis, and we demonstrate how incorporating it brings many benefits. Specifically, the UA facilitates efficient and robust computation—estimating the unimodal distribution involves solving a simple convex optimization problem—and enables more accurate inferences provided that it holds. Second, the method takes as its input two numbers for each test (an effect size estimate and corresponding standard error), rather than the one number usually used (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$p$\\end{document} value or \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$z$\\end{document} score). When available, using two numbers instead of one helps account for variation in measurement precision across tests. It also facilitates estimation of effects, and unlike standard FDR methods, our approach provides interval estimates (credible regions) for each effect in addition to measures of significance. To provide a bridge between interval estimates and significance measures, we introduce the term “local false sign rate” to refer to the probability of getting the sign of an effect wrong and argue that it is a superior

  14. Apparent-Strain Correction for Combined Thermal and Mechanical Testing

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; O'Neil, Teresa L.

    2007-01-01

    Combined thermal and mechanical testing requires that the total strain be corrected for the coefficient of thermal expansion mismatch between the strain gage and the specimen or apparent strain when the temperature varies while a mechanical load is being applied. Collecting data for an apparent strain test becomes problematic as the specimen size increases. If the test specimen cannot be placed in a variable temperature test chamber to generate apparent strain data with no mechanical loads, coupons can be used to generate the required data. The coupons, however, must have the same strain gage type, coefficient of thermal expansion, and constraints as the specimen to be useful. Obtaining apparent-strain data at temperatures lower than -320 F is challenging due to the difficulty to maintain steady-state and uniform temperatures on a given specimen. Equations to correct for apparent strain in a real-time fashion and data from apparent-strain tests for composite and metallic specimens over a temperature range from -450 F to +250 F are presented in this paper. Three approaches to extrapolate apparent-strain data from -320 F to -430 F are presented and compared to the measured apparent-strain data. The first two approaches use a subset of the apparent-strain curves between -320 F and 100 F to extrapolate to -430 F, while the third approach extrapolates the apparent-strain curve over the temperature range of -320 F to +250 F to -430 F. The first two approaches are superior to the third approach but the use of either of the first two approaches is contingent upon the degree of non-linearity of the apparent-strain curve.

  15. Geographic variation in apparent competition between native and invasive Phragmites australis.

    PubMed

    Bhattarai, Ganesh P; Meyerson, Laura A; Cronin, James T

    2017-02-01

    Apparent competition, the negative interaction between species mediated by shared natural enemies, is thought to play an important role in shaping the structure and dynamics of natural communities. However, its importance in driving species invasions, and whether the strength of this indirect interaction varies across the latitudinal range of the invasion, has not been fully explored. We performed replicated field experiments at four sites spanning 900 km along the Atlantic Coast of the United States to assess the presence and strength of apparent competition between sympatric native and invasive lineages of Phragmites australis. Four herbivore guilds were considered: stem-feeders, leaf-miners, leaf-chewers and aphids. We also tested the hypothesis that the strength of this interaction declines with increasing latitude. Within each site, native and invasive plants of P. australis were cross-transplanted between co-occurring native and invasive patches in the same marsh habitat and herbivore damage was evaluated at the end of the growing season. Apparent competition was evident for both lineages and involved all but the leaf-chewer guild. For native plants, total aphids per plant was 296% higher and the incidence of stem-feeding and leaf-mining herbivores was 34% and 221% higher, respectively, when transplanted into invasive than native patches. These data suggest that invasive P. australis has a negative effect on native P. australis via apparent competition. Averaged among herbivore types, the indirect effects of the invasive lineage on the native lineage was 57% higher than the reverse situation, suggesting that apparent competition was asymmetric. We also found that the strength of apparent competition acting against the native lineage was comparable to the benefits to the invasive lineage from enemy release (i.e., proportionately lower mean herbivory of the invasive relative to the native taxa). Finally, we found the first evidence that the strength of

  16. 'Endurance Crater's' Dazzling Dunes (false-color)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    As NASA's Mars Exploration Rover Opportunity creeps farther into 'Endurance Crater,' the dune field on the crater floor appears even more dramatic. This false-color image taken by the rover's panoramic camera shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a 'blue' tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules ('blueberries') that accumulate on the flat surfaces.

    Sinuous tendrils of sand less than 1 meter (3.3 feet) high extend from the main dune field toward the rover. Scientists hope to send the rover down to one of these tendrils in an effort to learn more about the characteristics of the dunes. Dunes are a common feature across the surface of Mars, and knowledge gleaned from investigating the Endurance dunes close-up may apply to similar dunes elsewhere.

    Before the rover heads down to the dunes, rover drivers must first establish whether the slippery slope that leads to them is firm enough to ensure a successful drive back out of the crater. Otherwise, such hazards might make the dune field a true sand trap.

  17. False vacuum as an unstable state

    NASA Astrophysics Data System (ADS)

    Urbanowski, K.

    2016-11-01

    Calculations performed within the Standard Model suggest that the electroweak vacuum is unstable if MH < 126 GeV, (MH is the mass of the Higgs particle). LHC discovery of the Higgs boson indicates that MH ≃ 125 GeV. So the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory. At asymptotically late times the survival probability as a function of time t has an inverse power-like form. We show that at this time region the energy of the false vacuum states tends to the energy of the true vacuum state as 1/t2 for t → ∞. This means that the energy density in the unstable vacuum state should have analogous properties and hence the cosmological constant Λ = Λ(t) too. So Λ in the Universe with the unstable vacuum should have a form of the sum of the "bare" cosmological constant and of the term of a type 1/t^2:Λ (t) ≡ Λbare + d/t^2, (where Λbare is the cosmological constant for the Universe with the true vacuum).

  18. Earth - False Color Mosaic of the Andes

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This false-color mosaic of the central part of the Andes mountains of South America (70 degrees west longitude, 19 degrees south latitude) is made up of 42 images acquired by the Galileo spacecraft from an altitude of about 25,000 kilometers (15,000 miles). A combination of visible (green) and near-infrared (0.76 and 1.0-micron) filters was chosen for this view to separate regions with distinct vegetation and soil types. The mosaic shows the area where Chile, Peru and Bolivia meet. The Pacific Coast appears at the left of the image-- Galileo captured this view as it traveled west over the Pacific Ocean, looking back at the Andes. Lakes Titicaca and Poopo are nearly black patches at the top and center, respectively; a large light-blue area below and to the left of Lake Poopo is Salar de Uyuni, a dry salt lake some 120 kilometers (75 miles) across. These lakes lie in the Altiplano, a region between the western and eastern Andes, which are covered by clouds. The vegetation-bearing Gran Chaco plains east of the Andes appear pale green. Light-blue patches in the mountains to the north are glaciers.

  19. Deep Hole in 'Clovis' (False Color)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    At a rock called 'Clovis,' the rock abrasion tool on NASA's Mars Exploration Rover Spirit cut a 9-millimeter (0.35-inch) hole during the rover's 216th martian day, or sol (Aug. 11, 2004). The hole is the deepest drilled in a rock on Mars so far. This false color view was made from images taken by Spirit's panoramic camera on sol 226 (Aug. 21, 2004) at around 12:50 p.m. local true solar time -- early afternoon in Gusev Crater on Mars. To the right is a 'brush flower' of circles produced by scrubbing the surface of the rock with the abrasion tool's wire brush. Scientists used rover's Moessbauer spectrometer and alpha particle X-ray spectrometer to look for iron-bearing minerals and determine the elemental chemical composition of the rock. This composite combines images taken with the camera's 750-, 530-, and 430-nanometer filters. The grayish-blue hue in this image suggests that the interior of the rock contains iron minerals that are less oxidized than minerals on the surface. The diameter of the hole cut into the rock is 4.5 centimeters (1.8 inches).

  20. The False Security of Blind Dates

    PubMed Central

    Cimino, J.J.

    2012-01-01

    Background The reuse of clinical data for research purposes requires methods for the protection of personal privacy. One general approach is the removal of personal identifiers from the data. A frequent part of this anonymization process is the removal of times and dates, which we refer to as “chrononymization.” While this step can make the association with identified data (such as public information or a small sample of patient information) more difficult, it comes at a cost to the usefulness of the data for research. Objectives We sought to determine whether removal of dates from common laboratory test panels offers any advantage in protecting such data from re-identification. Methods We obtained a set of results for 5.9 million laboratory panels from the National Institutes of Health’s (NIH) Biomedical Translational Research Information System (BTRIS), selected a random set of 20,000 panels from the larger source sets, and then identified all matches between the sets. Results We found that while removal of dates could hinder the re-identification of a single test result, such removal had almost no effect when entire panels were used. Conclusions Our results suggest that reliance on chrononymization provides a false sense of security for the protection of laboratory test results. As a result of this study, the NIH has chosen to rely on policy solutions, such as strong data use agreements, rather than removal of dates when reusing clinical data for research purposes. PMID:23646086

  1. False-color composite of Oetztal, Austria

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image is a false-color composite of Oetztal, Austria located in the Central Alps centered at 46.8 degrees north latitude, 10.70 degrees east longitude, at the border between Switzerland (top), Italy (left) and Austria (right and bottom). The area shown is 50 kilometers (30 miles) south of Inssbruck, Austria. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperature Radar (SIR-C/X-SAR) flying on the Space Shuttle Endeavour on its 14th orbit. Approximately one quarter of this image is covered by glaciers, the largest of which, Gepatschferner, is visible as a triangular yellow patch in the center of the scene. The blue areas are lakes (Gepatsch dam at center right; Lake Muta at top right) and glacier ice. The yellow areas are slopes facing the radar and areas of dry snow. Purple corresponds to slopes facing away from the radar. Yellow in the valley bottom corresponds to tree covered areas. The Jet Propulsion Laboratory alternative photo number is P-43890.

  2. Possible and False Biomarkers from Space

    NASA Technical Reports Server (NTRS)

    Bernstein, Max P.

    2004-01-01

    The Search for life in the Solar System is one of NASA's main goals for the coming decade. We may never observe alien life directly; we or our robotic craft may always be removed from it by many years, or meters of crust. If we do find evidence of Life elsewhere in the Solar System it will probably be in form of chemical biomarkers, quintessentially biological molecules that indicate the presence of micro-organisms. What molecules would be truly indicative of alien life? Chlorophyll fragments, which are often used by geochemists are probably far too specific. Simpler molecules, such as fatty acids, amino acids and nucleo-bases might seem to be biomarkers, but they can form non-biotically in space. Alkyl substituted aromatics in ALH 84001 have been invoked as biomarkers, but they are not strong evidence in and of themselves. Understanding the range of nonbiological organic molecules which could act as false biomarkers in space is a prerequisite for any reasonable search for true biomarkers on other worlds. When simple organics arrive at the surface of a body like Europa, either from below or from space, how long do they survive and what do they make? How can we distinguish these from real biomarkers? In this talk I will present some ideas about what might be useful qualities to consider in a potential biomarker, and will ask for advice from the attendant geochemists.

  3. Avoiding the False Peaks in Correlation Discrimination

    SciTech Connect

    Awwal, A S

    2009-07-31

    Fiducials imprinted on laser beams are used to perform video image based alignment of the 192 laser beams in the National Ignition Facility (NIF) of Lawrence Livermore National Laboratory. In many video images, matched filtering is used to detect the location of these fiducials. Generally, the highest correlation peak is used to determine the position of the fiducials. However, when the signal to-be-detected is very weak compared to the noise, this approach totally breaks down. The highest peaks act as traps for false detection. The active target images used for automatic alignment in the National Ignition Facility are examples of such images. In these images, the fiducials of interest exhibit extremely low intensity and contrast, surrounded by high intensity reflection from metallic objects. Consequently, the highest correlation peaks are caused by these bright objects. In this work, we show how the shape of the correlation is exploited to isolate the valid matches from hundreds of invalid correlation peaks, and therefore identify extremely faint fiducials under very challenging imaging conditions.

  4. Apparent mass and cross-axis apparent mass of standing subjects during exposure to vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Subashi, G. H. M. J.; Matsumoto, Y.; Griffin, M. J.

    2006-05-01

    The effects of posture and vibration magnitude on the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the standing human body during exposure to vertical vibration have been investigated. Twelve male subjects were exposed to random vertical vibration over the frequency range 2.0-20 Hz at three vibration magnitudes: 0.125, 0.25 and 0.5 m s -2 rms. Subjects stood in five different postures: upright, lordotic, anterior lean, knees bent and knees more bent. The vertical acceleration at the floor and the forces in the vertical and fore-and-aft directions at the floor were used to obtain the apparent mass and the cross-axis apparent mass. The resonance frequency of the apparent mass was significantly reduced with knees bent and knees more bent postures, but there were only minor effects on the resonance frequency by changing the position of the upper body. Considerable cross-axis apparent mass, up to about 30% of the static mass of subjects, was found. The cross-axis apparent mass was influenced by all postural changes used in the study. In all postures the resonance frequencies of the apparent mass and the cross-axis apparent mass tended to decrease with increasing vibration magnitude. This nonlinear characteristic tended to be less clear in some postures in which subjects increased muscle tension.

  5. Siblings, language, and false belief in low-income children.

    PubMed

    Tompkins, Virginia; Farrar, M Jeffrey; Guo, Ying

    2013-01-01

    The authors examined the relationship between number of siblings and false belief understanding (FBU) in 94 low-income 4-5-year-olds. Previous research with middle-income children has shown a positive association between number of siblings and FBU. However, it is unclear whether having multiple siblings in low-income families is related to better FBU. Language, specifically vocabulary, was examined as a possible mediator between number of siblings and FBU as several researchers have found that language is causally related to FBU. Contrary to research with middle-income preschoolers, the authors found that number of siblings was negatively related to low-income children's FBU. This relationship was mediated by children's vocabulary skill. Suggestions for why the sibling-FB relationship may differ in low- and middle-income samples are offered.

  6. Masking and color inheritance along the apparent motion path.

    PubMed

    Souto, David; Johnston, Alan

    2012-07-30

    Long-range apparent motion is the illusory motion that can be perceived when two static and distant stimuli are presented in succession. Within some spatiotemporal range not only is motion sensed, but it appears as if one stimulus is displaced from one place to another (termed beta or optimal motion). Several groups have found that this illusory percept can interact with perception of a physically present stimulus, but some disagree on the origin of these interactions. We know little about how suppressive effects depend on feature-similarity between a target and the stimuli in apparent motion (inducers)-which would indicate an early perceptual locus-or even about the minimal conditions under which to obtain this effect. Unlike early studies that used a two-stroke apparent motion paradigm, we were able to demonstrate that motion can mask stimuli presented at interpolated locations along the apparent motion path, as shown by the elevation of contrast thresholds compared to a control condition. Apparent motion masking depended on color similarity between target and inducers. Further, we found evidence that the color of inducers alters the apparent color of intervening gray probes, indicating some inheritance or chromatic averaging across distant locations, but no clear evidence of predictive updating. Finally, the analysis of the presentation times delivering maximal masking effects suggests a predictive interpolation process is responsible for interference by apparent motion filling-in. We discuss alternative mechanisms, in particular the possible role of apparent-motion-induced metacontrast masking in generating this pattern of results.

  7. Consequences of treating false positive heparin-induced thrombocytopenia.

    PubMed

    Marler, Jacob; Unzaga, Jessica; Stelts, Sundae; Oliphant, Carrie S

    2015-11-01

    Identification of patients with heparin-induced thrombocytopenia is encumbered by false positive enzyme-linked immuno assay (ELISA) antibody results, therefore a serotonin release assay (SRA) is used for confirmation. Recently, several studies have demonstrated that increasing the optical density (OD) threshold (currently at 0.4) of the antibody test enhances the positive predictive value. The purpose of this study was to determine the frequency of patients who were ELISA antibody positive but SRA negative, and the costs and bleeding events associated with alternative anticoagulant treatment. We hypothesized that treating patients with a positive ELISA antibody OD value of <1.0 would result in increased cost and bleeding risk. This retrospective chart review was conducted on adult hospitalized patients from 2011 to 2013. Patients with positive ELISA antibodies (OD of 0.4-1.0) and an SRA result were included. Eighty-five patients were identified with positive antibodies (average OD of 0.66), 100 % of which were found to be SRA negative. A total of 59 patients (69 %) received alternative anticoagulants. The average duration of treatment was 3.1 days, and 4 patients (4.7 %) experienced a bleeding event. The cost of testing and laboratory monitoring was $36,346 and the cost of the alternative anticoagulants totaled $47,179. The total cost was $83,525, with an average total cost per patient of $982. This study adds to the body of literature suggesting treatment should only be initiated if the OD is one or greater. The high false positive rate caused increased cost and some bleeding events.

  8. Excluding False Positive Detections in Kepler Data

    NASA Astrophysics Data System (ADS)

    Caldwell, John J.; Ouvarova, T.; Borucki, W. J.

    2006-09-01

    The NASA Kepler Mission, scheduled for launch in 2008, will search for Earth-size planets orbiting Sun-like stars in or near habitable zones. A high precision photometer will search for planetary transits of parent stars. For a system similar to the Earth-Sun, the decrease in light during a central transit will be one part in 10,000 of the total stellar brightness out of transit. This poster discusses the effort to address a significant concern: the possibility of false positive detections of extra-solar Earth analogs. The concern arises because about 50 per cent of star systems are double or multiple. Further, because the photometer design is constrained by the requirement for high sensitivity to changes of low light levels, the optical resolution is not high compared to other space or terrestrial telescopes. If a relatively nearby Kepler target star happens to contain, within the Kepler PSF, an eclipsing binary system that is reduced in brightness by a factor of 10,000, say because it is 100 times farther away, the photometric profile of an eclipse could mimic a planetary transit. We have therefore developed a program to use archival data from the Hubble Space Telescope to quantify the number density of faint stars in the Kepler field that are in the brightness range that could cause confusion. Since the beginning of the project, the location of the Kepler field itself has been changed to optimize observing efficiency. The work originally included HST/WFPC2 data, and has now been expanded to ACS data as well. We present here a summary of completed and continuing work on faint background systems in the new Kepler field.

  9. Blue Polar Dunes In False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    The small dunes in this image are 'bluer' than the rest of the layered ice/dust units to the left.

    Image information: VIS instrument. Latitude 84.5, Longitude 206.6 East (153.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Dunes and Clouds in False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    The small greenish features in this image are sand dunes. The white feature on the right side is likely an ice cloud.

    Image information: VIS instrument. Latitude 84.6, Longitude 203.1 East (156.9 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. A Frosty Rim In False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    Our final image combines the features of the past two days, with a dust covered frosty crater rim and the bluer sand dunes of the north polar region.

    Image information: VIS instrument. Latitude 70.1, Longitude 351.8 East (8.2 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Controlling the Rate of GWAS False Discoveries

    PubMed Central

    Brzyski, Damian; Peterson, Christine B.; Sobczyk, Piotr; Candès, Emmanuel J.; Bogdan, Malgorzata; Sabatti, Chiara

    2017-01-01

    With the rise of both the number and the complexity of traits of interest, control of the false discovery rate (FDR) in genetic association studies has become an increasingly appealing and accepted target for multiple comparison adjustment. While a number of robust FDR-controlling strategies exist, the nature of this error rate is intimately tied to the precise way in which discoveries are counted, and the performance of FDR-controlling procedures is satisfactory only if there is a one-to-one correspondence between what scientists describe as unique discoveries and the number of rejected hypotheses. The presence of linkage disequilibrium between markers in genome-wide association studies (GWAS) often leads researchers to consider the signal associated to multiple neighboring SNPs as indicating the existence of a single genomic locus with possible influence on the phenotype. This a posteriori aggregation of rejected hypotheses results in inflation of the relevant FDR. We propose a novel approach to FDR control that is based on prescreening to identify the level of resolution of distinct hypotheses. We show how FDR-controlling strategies can be adapted to account for this initial selection both with theoretical results and simulations that mimic the dependence structure to be expected in GWAS. We demonstrate that our approach is versatile and useful when the data are analyzed using both tests based on single markers and multiple regression. We provide an R package that allows practitioners to apply our procedure on standard GWAS format data, and illustrate its performance on lipid traits in the North Finland Birth Cohort 66 cohort study. PMID:27784720

  13. Spirit View of 'Wishstone' (False Color)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1

    Scientists working with NASA's Mars Exploration Rover Spirit decided to examine this rock, dubbed 'Wishstone,' based on data from the miniature thermal emission spectrometer. That instrument's data indicated that the mineralogy of the rocks in this area is different from that of rocks encountered either on the plains of Gusev Crater or in bedrock outcrops examined so far in the 'Columbia Hills' inside the crater. Spirit used its rock abrasion tool first to scour a patch of the rock's surface with a wire brush, then to grind away the surface to reveal interior material. Placement of the rover's alpha particle X-ray spectrometer on the exposed circle of interior material revealed that the rock is rich in phosphorus. Spirit used its panoramic camera during the rover's 342nd martian day, or sol, (Dec. 18, 2004) to take the three individual images that were combined to produce this false-color view emphasizing the freshly ground dust around the hole cut by the rock abrasion tool.

    Unusually Rich in Phosophorus The graph in figure 1 compares the elemental makeup of a rock dubbed 'Wishstone' with the average composition of rocks that Spirit examined on the western spur of the 'Columbia Hills.' Wishstone lies farther into the hills than that spur. It is richer in phosphorus than any other Mars rock ever examined. Scientists plan to examine other rocks near Wishstone to help explain the significance of the high phosphorus concentration. The vertical scale is the ratio of the concentration of an element in the hills rocks to the concentration of the same element in a typical volcanic rock from the plains that Spirit crossed to reach the hills.

  14. Natural and False Color Views of Europa

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This image shows two views of the trailing hemisphere of Jupiter's ice-covered satellite, Europa. The left image shows the approximate natural color appearance of Europa. The image on the right is a false-color composite version combining violet, green and infrared images to enhance color differences in the predominantly water-ice crust of Europa. Dark brown areas represent rocky material derived from the interior, implanted by impact, or from a combination of interior and exterior sources. Bright plains in the polar areas (top and bottom) are shown in tones of blue to distinguish possibly coarse-grained ice (dark blue) from fine-grained ice (light blue). Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. This crater has been provisionally named 'Pwyll' for the Celtic god of the underworld.

    Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon. This image was taken on September 7, 1996, at a range of 677,000 kilometers (417,900 miles) by the solid state imaging television camera onboard the Galileo spacecraft during its second orbit around Jupiter. The image was processed by Deutsche Forschungsanstalt fuer Luftund Raumfahrt e.V., Berlin, Germany.

    The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo

  15. Blind sequential lineup administration reduces both false identifications and confidence in those false identifications.

    PubMed

    Charman, Steve D; Quiroz, Vanessa

    2016-10-01

    One of the most recommended procedures proposed by eyewitness experts is the use of double-blind lineups, in which the administrator does not know the identity of the suspect in the lineup. But despite the near universality of this recommendation, there is surprisingly little empirical research to support the claim that nonblind administration inflates false identifications. What little research has been conducted has shown conflicting findings with regard to the conditions under which nonblind administration affects false identifications, as well as its effects on witness confidence. The current study attempts to elucidate this effect. Student-participants (n = 312) were randomly assigned to play the role of either a lineup administrator (who were either told the identity of the suspect in the lineup or not) or a mock crime witness. Following unbiased instructions, administrators presented either a target-present or target-absent sequential lineup to the witness while being surreptitiously videorecorded. Nonblind administration significantly inflated false, but not correct, identifications, and significantly inflated witness confidence in those false identifications. Video recordings indicated that nonblind administrators were significantly more likely than blind administrators to smile (a) while the witness was viewing a photograph of the suspect, and (b) after a suspect identification. Results provide stronger support for the use of blind lineup administration by broadening the conditions under which nonblind administration is shown to inflate false identifications. Possible reconciliations for conflicting findings in the literature are discussed. (PsycINFO Database Record

  16. Multiple Weather Factors Affect Apparent Survival of European Passerine Birds

    PubMed Central

    Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

    2013-01-01

    Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for

  17. Multiple weather factors affect apparent survival of European passerine birds.

    PubMed

    Salewski, Volker; Hochachka, Wesley M; Fiedler, Wolfgang

    2013-01-01

    Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for

  18. Statistical approaches to account for false-positive errors in environmental DNA samples.

    PubMed

    Lahoz-Monfort, José J; Guillera-Arroita, Gurutzeta; Tingley, Reid

    2016-05-01

    Environmental DNA (eDNA) sampling is prone to both false-positive and false-negative errors. We review statistical methods to account for such errors in the analysis of eDNA data and use simulations to compare the performance of different modelling approaches. Our simulations illustrate that even low false-positive rates can produce biased estimates of occupancy and detectability. We further show that removing or classifying single PCR detections in an ad hoc manner under the suspicion that such records represent false positives, as sometimes advocated in the eDNA literature, also results in biased estimation of occupancy, detectability and false-positive rates. We advocate alternative approaches to account for false-positive errors that rely on prior information, or the collection of ancillary detection data at a subset of sites using a sampling method that is not prone to false-positive errors. We illustrate the advantages of these approaches over ad hoc classifications of detections and provide practical advice and code for fitting these models in maximum likelihood and Bayesian frameworks. Given the severe bias induced by false-negative and false-positive errors, the methods presented here should be more routinely adopted in eDNA studies.

  19. 'Lyell' Panorama inside Victoria Crater (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce this view, which is presented in a false-color stretch to bring out subtle color differences in the scene. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

  20. False Color Mosaic Great Red Spot

    NASA Technical Reports Server (NTRS)

    1996-01-01

    False color representation of Jupiter's Great Red Spot (GRS) taken through three different near-infrared filters of the Galileo imaging system and processed to reveal cloud top height. Images taken through Galileo's near-infrared filters record sunlight beyond the visible range that penetrates to different depths in Jupiter's atmosphere before being reflected by clouds. The Great Red Spot appears pink and the surrounding region blue because of the particular color coding used in this representation. Light reflected by Jupiter at a wavelength (886 nm) where methane strongly absorbs is shown in red. Due to this absorption, only high clouds can reflect sunlight in this wavelength. Reflected light at a wavelength (732 nm) where methane absorbs less strongly is shown in green. Lower clouds can reflect sunlight in this wavelength. Reflected light at a wavelength (757 nm) where there are essentially no absorbers in the Jovian atmosphere is shown in blue: This light is reflected from the deepest clouds. Thus, the color of a cloud in this image indicates its height. Blue or black areas are deep clouds; pink areas are high, thin hazes; white areas are high, thick clouds. This image shows the Great Red Spot to be relatively high, as are some smaller clouds to the northeast and northwest that are surprisingly like towering thunderstorms found on Earth. The deepest clouds are in the collar surrounding the Great Red Spot, and also just to the northwest of the high (bright) cloud in the northwest corner of the image. Preliminary modeling shows these cloud heights vary over 30 km in altitude. This mosaic, of eighteen images (6 in each filter) taken over a 6 minute interval during the second GRS observing sequence on June 26, 1996, has been map-projected to a uniform grid of latitude and longitude. North is at the top.

    Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet

  1. Spirit's West Valley Panorama (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle

  2. Panorama from 'Cape Verde' (False Color)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Opportunity captured this vista of 'Victoria Crater' from the viewpoint of 'Cape Verde,' one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).

    The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. 'Duck Bay,' where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is 'Cabo Frio,' about 150 meters (500 feet) from the rover. On the left side of the panorama is 'Cape St. Mary,' the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.

    The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.

    This view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet). It is presented in false

  3. Impact of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography Before and After Definitive Radiation Therapy in Patients With Apparently Solitary Plasmacytoma

    SciTech Connect

    Kim, Paul J.; Hicks, Rodney J.; Wirth, Andrew; Ryan, Gail; Seymour, John F.; Prince, H. Miles

    2009-07-01

    Purpose: To evaluate the impact of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) on management of patients with apparently isolated plasmacytoma. Methods and Materials: Twenty-one patients with apparently solitary plasmacytoma who underwent FDG-PET for staging or restaging were identified from a central PET database. They were either candidates for or had received definitive radiation therapy (RT). Results: Seventeen patients had initial staging scans for bone (n = 11) or soft tissue (n = 6) plasmacytomas, and 11 had PET scans after RT. Only 1 of 14 known untreated sites of plasmacytoma was not identified on staging PET (lesion sensitivity = 93%). Three plasmacytomas were excised before PET. Staging PET influenced management in 6 of 17 patients (35%) by showing multiple myeloma (n = 1), discouraging RT after complete resection (n = 1), excluding plasmacytoma at a second site (n = 1), by increasing RT fields (n = 2), or by suggesting sarcoidosis (n = 1). Fifteen of 17 patients with initial staging PET scans received definitive RT. Restaging PET scans after RT showed complete metabolic response in 8 of 11 cases and progressive disease in 2. Two patients with either no response or partial metabolic response had late responses. Staging sestamibi and PET scans were concordant in five of six occasions (one sestamibi scan was false negative). Conclusions: FDG-PET has value for staging and RT planning in plasmacytoma and potentially could have a role in response-assessment after RT. Slow resolution of FDG uptake posttreatment does not necessarily imply an adverse prognosis.

  4. Gusev Rocks Solidified from Lava (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    to identify rocks and features investigated by Spirit during the Chinese New Year celebration period. In ancient Chinese myth, FuYi was the first great emperor and lived in the east. He explained the theory of 'Yin' and 'Yang' to his people, invented the net to catch fish, was the first to use fire to cook food, and invented a musical instrument known as the 'Se' to accompany his peoples' songs and dances. Other rocks and features are being informally named for Chinese gods, warriors, inventors, and scientists, as well as rivers, lakes, and mountains.

    Spirit took this image on the rover's Martian day, or sol, 731 (Jan. 23, 2006). This is a false-color composite combining images taken with the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters.

  5. Do Optimal Prognostic Thresholds in Continuous Physiological Variables Really Exist? Analysis of Origin of Apparent Thresholds, with Systematic Review for Peak Oxygen Consumption, Ejection Fraction and BNP

    PubMed Central

    Leong, Tora; Rehman, Michaela B.; Pastormerlo, Luigi Emilio; Harrell, Frank E.; Coats, Andrew J. S.; Francis, Darrel P.

    2014-01-01

    Background Clinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies. Objectives We studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO2), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF). Data Sources and Eligibility Criteria Studies testing pVO2, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed. Methods First, we examined studies testing pVO2, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk. Results 33 studies (8946 patients) tested a pVO2 threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10–18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO2 (r = 0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p = 0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r = 0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r = 0.86 (p<0.0001). Second, survival simulations always discovered a “most significant” threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r = 0.99, p<0.001). Limitations This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds. Key Findings First, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO2, EF or BNP. Second

  6. 40 CFR 52.2900 - Negative declaration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Negative declaration. 52.2900 Section... § 52.2900 Negative declaration. (a) Air Pollution Implementation Plan for the Commonwealth of the Northern Mariana Islands. (1) Letter of December 15, 1982, from the Governor to EPA, which is a...

  7. The Influence of Feedback of Diagnosis and Executive Function Skills on Rates of False Positive and False Negative Outcomes for ADHD

    ERIC Educational Resources Information Center

    Bender, Stacy L.; Privitera, Gregory J.

    2016-01-01

    This study examined executive function (EF) skills and self-reported symptoms of ADHD. EF skills were measured to determine whether skills were different between groups that reported clinical levels of ADHD symptoms (clinical group) and nonclinical levels of ADHD symptoms (nonclinical group). EF skills in the nonclinical group were also…

  8. Apparent Biological Motion in First and Third Person Perspective

    PubMed Central

    Scandola, Michele; Orvalho, Veronica; Candidi, Matteo

    2016-01-01

    Apparent biological motion is the perception of plausible movements when two alternating images depicting the initial and final phase of an action are presented at specific stimulus onset asynchronies. Here, we show lower subjective apparent biological motion perception when actions are observed from a first relative to a third visual perspective. These findings are discussed within the context of sensorimotor contributions to body ownership. PMID:27708754

  9. False Memory ≠ False Memory: DRM Errors Are Unrelated to the Misinformation Effect

    PubMed Central

    Ost, James; Blank, Hartmut; Davies, Joanna; Jones, Georgina; Lambert, Katie; Salmon, Kelly

    2013-01-01

    The DRM method has proved to be a popular and powerful, if controversial, way to study ‘false memories’. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r  = −.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM ‘false memories’ and misinformation effect ‘false memories’ do not appear to be equivalent. PMID:23573186

  10. An Improved Comprehensive Model for the Apparent Viscosity of Blood

    NASA Astrophysics Data System (ADS)

    Jacobitz, Frank; Anderson, Spencer

    2008-11-01

    An improved comprehensive model for the apparent viscosity of blood is developed and used in simulations of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia. In the microcirculation, the apparent viscosity of blood depends on the local vessel diameter, hematocrit, and shear rate. The proposed comprehensive model extends the apparent viscosity model developed by Pries, Secomb, Gaehtgens, and Gross (Circulation Research, 67, 826-834, 1990), which describes the effect of vessel diameter and hematocrit on the apparent viscosity. A shear thinning term is developed using the experimental data of Lipowsky, Usami, and Chien (Microvascular Research, 19, 297-319, 1980). Curve fits of this data can be combined with equations given in the Pries et al. work to create a system of equations that can be used to find the shear thinning factor. The simulations based on the improved apparent viscosity model use realistic vessel topology for the microvasculature, reconstructed from microscope images of tissue samples, and consider passive and active vessel properties. The numerical method is based on a Hagen-Poiseuille balance in the microvessels and a sparse matrix solver is used to obtain the solution. It was found that the inclusion of the shear factor decreases the overall flowrate in the capillary bundle. Many vessel connections in the fascia are characterized by relatively low shear rates and therefore increased apparent viscosity.

  11. Visual content of words delays negation.

    PubMed

    Orenes, Isabel; Santamaría, Carlos

    2014-11-01

    Many studies have shown the advantage of processing visualizable words over non-visualizables due to the associated image code. The present paper reports the case of negation in which imagery could slow down processing. Negation reverses the truth value of a proposition from false to true or vice versa. Consequently, negation works only on propositions (reversing their truth value) and cannot apply directly to other forms of knowledge representation such as images (although they can be veridical or not). This leads to a paradoxical hypothesis: despite the advantage of visualizable words for general processing, the negation of clauses containing words related to the representation of an image would be more difficult than negation containing non-visualizable words. Two experiments support this hypothesis by showing that sentences with a previously negated visualizable word took longer to be read than sentences with previously negated non-visualizable words. The results suggest that a verbal code is used to process negation.

  12. Product design and apparent usability. The influence of novelty in product appearance.

    PubMed

    Mugge, Ruth; Schoormans, Jan P L

    2012-11-01

    This research enhances our understanding of the relationship between aesthetics and usability by investigating the effects of novelty in product appearance on the apparent usability of a product. In two experimental studies using washing machines and digital cameras as stimuli, we systematically manipulated the level of novelty (low vs. high) in the product appearance by changing the product's color or shape. Participants were presented with one of these product appearances and a list of the product's technical specifications. Next, participants indicated how difficult or easy they expected the usage of the product to be. Our findings demonstrate that because people associate a high level of novelty with technological advancement, novelty in a product appearance negatively affects their expectations of a product's usability at the point of sale. Furthermore, novices are more likely to use the level of novelty as a cue for a product's apparent usability than experts.

  13. False-evidence ploys and interrogations: mock jurors' perceptions of false-evidence ploy type, deception, coercion, and justification.

    PubMed

    Forrest, Krista D; Woody, William Douglas; Brady, Sara E; Batterman, Keller C; Stastny, Bradley J; Bruns, Jennifer A

    2012-01-01

    We studied mock jurors' evaluations of police false-evidence ploys across two false-evidence ploy information conditions (true or false confession). Study 1 participants evaluated lists of demeanor, testimonial, and scientific ploys and rated testimonial false-evidence ploys as more coercive than demeanor false-evidence ploys. Participants in the false-confession condition rated false-evidence ploys as more deceptive than did participants in the true-confession condition. Study 2 participants evaluated false-evidence ploy types within interrogation transcripts. Participants rated testimonial false-evidence ploys as more deceptive and coercive than demeanor false-evidence ploys; participants in the true-confession condition rated false-evidence ploys as more justified. Across studies, participants reading realistic transcripts rated false-evidence ploys as more deceptive and coercive. We discuss implications for scholars, attorneys, and interrogators.

  14. Effect of reactivity loss on apparent reaction order of burning char particles

    SciTech Connect

    Murphy, Jeffrey J.; Shaddix, Christopher R.

    2010-03-15

    Considerable debate still exists in the char combustion community over the expected and observed reaction orders of carbon reacting with oxygen. In particular, very low values of the reaction order (approaching zero) are commonly observed in char combustion experiments. These observations appear to conflict with porous catalyst theory as first expressed by Thiele, which suggests that the apparent reaction order must be greater than 0.5. In this work, we propose that this conflict may be resolved by considering the decrease in char reactivity with burnout due to ash effects, thermal annealing, or other phenomena. Specifically, the influence of ash dilution of the available surface area on the apparent reaction order is explored. Equations describing the ash dilution effect are combined with a model for particle burnout based on single-film nth-order Arrhenius char combustion and yield an analytical expression for the effective reaction order. When this expression is applied for experimental conditions reflecting combustion of individual pulverized coal particles in an entrained flow reactor, the apparent reaction order is shown to be lower than the inherent char matrix reaction order, even for negligible extents of char conversion. As char conversion proceeds and approaches completion, the apparent reaction order drops precipitously past zero to negative values. Conversely, the inclusion of the ash dilution model has little effect on the char conversion profile or char particle temperature until significant burnout has occurred. Taken together, these results suggest that the common experimental observation of low apparent reaction orders during char combustion is a consequence of the lack of explicit modeling of the decrease in char reactivity with burnout. (author)

  15. Variation in the apparent density of human mandibular bone with age and dental status

    PubMed Central

    KINGSMILL, V. J.; BOYDE, A.

    1998-01-01

    This study examines the variability in the anatomy of mandibles of differing ages and different stages of tooth loss. Mandibles from individuals between 19 and 96 y were sectioned into 2 mm thick vertical plane-parallel slices and cleaned of marrow and periosteum. The apparent density (mass per unit volume in g/ml) from midline (MID) and mental foramen region (MF) sites was determined by weighing the slices and dividing by a volume calculated as the product of section thickness and the mean area of the 2 sides of the section. The cortical thickness of the inferior border and the basal and alveolar bone heights were measured in radiographs of the slices. Mandibular apparent density was negatively correlated with the cross sectional area (midline r=−0.48, mental foramen r=−0.45), and at the midline was significantly greater in edentulous than in dentate individuals (means (± s.e.m.) edentulous n=13: 1.43 (±0.07) g/ml; dentate n=17: 1.27 (±0.04) g/ml, P<0.05). Where a large enough age range was available, mandibular apparent bone density showed a significant increase with age (midline males: r=0.53, n=18) especially for dentate individuals (r=0.91, n=8). There was a correlation between the apparent densities at the two sites in the same mandible (r=0.64), with the values obtained for the midline being significantly greater than for the mental foramen region (midline 1.34 (±0.04) g/ml; mental foramen 1.19 (±0.04) g/ml, P<0.001, paired t test). The mandible shows great interindividual variability, but there may be a considerable reduction in cross sectional girth of the mandible following tooth loss, and, unlike postcranial sites, an increase in apparent density with age. PMID:9643424

  16. On Multiplying Negative Numbers.

    ERIC Educational Resources Information Center

    Crowley, Mary L.; Dunn, Kenneth A.

    1985-01-01

    Comments on the history of negative numbers, some methods that can be used to introduce the multiplication of negative numbers to students, and an explanation of why the product of two negative numbers is a positive number are included. (MNS)

  17. Falsely elevated troponin: rare occurrence or future problem

    PubMed Central

    Nguyen, James; Thachil, Rosy; Vyas, Neil; Marino, Thomas

    2016-01-01

    Introduction Troponins are known to be released in response to cardiac damage and therefore are the biomarkers of choice for the early diagnosis of acute myocardial infarction (AMI), improving outcome in patients presenting with chest pain. However, false results can occur due to interference from other substances in the blood. Case A 52-year-old male with a past medical history of alcohol abuse, hypertension, and coronary artery bypass graft at age 34 with normal stress test 2 years before presented to the emergency department (ED) complaining of 1 day of non-exertional chest pain with radiation to the neck and left arm. His troponin was elevated to 5 ng/mL in two samples drawn 12 h apart, with normal CK-MB. Renal function was normal. Electrocardiogram (ECG) showed normal sinus rhythm with no ST elevations or depressions. He underwent cardiac catheterization which showed no obstructive lesions. Five years later, he returned to the ED with abdominal pain and shortness of breath. Troponin was elevated and showed no signs of downtrend on repeat every 6 h. ECG was unchanged from 5 years before. He was discharged with a follow-up cardiac computed tomography (CT). Troponin was measured on the day of his scan and remained elevated; he was asymptomatic. Cardiac CT showed unremarkable coronaries and bypass grafts. Given persistently positive troponin in the setting of minimal to no symptoms, he was thought to have falsely elevated troponins. Centrifugation and 2:1 dilution of the sample resulted in the same general value, respectively. Rheumatoid factor and heterophile antibodies were negative. When his blood sample was sent to a different hospital utilizing a three-site immunoassay method, the value was found zero. Discussion Cardiac troponins (cTn) are structural proteins unique to the heart, not expressed outside of cardiac tissue and have high sensitivity and specificity for myocardial damage. Therefore, it is the test of choice for the diagnosis of AMI. When an

  18. Reflection and transmission at the apparent horizon during gravitational collapse

    SciTech Connect

    Vaz, Cenalo; Wijewardhana, L. C. R.

    2010-10-15

    We examine the wave functionals describing the collapse of a self-gravitating dustball in an exact quantization of the gravity-dust system. We show that ingoing (collapsing) dust shell modes outside the apparent horizon must necessarily be accompanied by outgoing modes inside the apparent horizon, whose amplitude is suppressed by the square root of the Boltzmann factor at the Hawking temperature. Likewise, ingoing modes in the interior must be accompanied by outgoing modes in the exterior, again with an amplitude suppressed by the same factor. A suitable superposition of the two solutions is necessary to conserve the dust probability flux across the apparent horizon; thus, each region contains both ingoing and outgoing dust modes. If one restricts oneself to considering only the modes outside the apparent horizon then one should think of the apparent horizon as a partial reflector, the probability for a shell to reflect being given by the Boltzmann factor at the Hawking temperature determined by the mass contained within it. However, if one considers the entire wave function, the outgoing wave in the exterior is seen to be the transmission through the horizon of the interior outgoing wave that accompanies the collapsing shells. This transmission could allow information from the interior to be transferred to the exterior.

  19. Adults' Memories of Childhood: True and False Reports

    ERIC Educational Resources Information Center

    Qin, Jianjian; Ogle, Christin M.; Goodman, Gail S.

    2008-01-01

    In 3 experiments, the authors examined factors that, according to the source-monitoring framework, might influence false memory formation and true/false memory discernment. In Experiment 1, combined effects of warning and visualization on false childhood memory formation were examined, as were individual differences in true and false childhood…

  20. 42 CFR 21.23 - False statements as disqualification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...

  1. 42 CFR 21.23 - False statements as disqualification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...

  2. 42 CFR 21.23 - False statements as disqualification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...

  3. 42 CFR 21.23 - False statements as disqualification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...

  4. 42 CFR 21.23 - False statements as disqualification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...

  5. An Examination of Negative Halo Error in Ratings.

    ERIC Educational Resources Information Center

    Lance, Charles E.; And Others

    1990-01-01

    A causal model of halo error (HE) is derived. Three hypotheses are formulated to explain findings of negative HE. It is suggested that apparent negative HE may have been misinferred from existing correlational measures of HE, and that positive HE is more prevalent than had previously been thought. (SLD)

  6. Meta-analysis of theory-of-mind development: the truth about false belief.

    PubMed

    Wellman, H M; Cross, D; Watson, J

    2001-01-01

    Research on theory of mind increasingly encompasses apparently contradictory findings. In particular, in initial studies, older preschoolers consistently passed false-belief tasks-a so-called "definitive" test of mental-state understanding-whereas younger children systematically erred. More recent studies, however, have found evidence of false-belief understanding in 3-year-olds or have demonstrated conditions that improve children's performance. A meta-analysis was conducted (N = 178 separate studies) to address the empirical inconsistencies and theoretical controversies. When organized into a systematic set of factors that vary across studies, false-belief results cluster systematically with the exception of only a few outliers. A combined model that included age, country of origin, and four task factors (e.g., whether the task objects were transformed in order to deceive the protagonist or not) yielded a multiple R of .74 and an R2 of .55; thus, the model accounts for 55% of the variance in false-belief performance. Moreover, false-belief performance showed a consistent developmental pattern, even across various countries and various task manipulations: preschoolers went from below-chance performance to above-chance performance. The findings are inconsistent with early competence proposals that claim that developmental changes are due to tasks artifacts, and thus disappear in simpler, revised false-belief tasks; and are, instead, consistent with theoretical accounts that propose that understanding of belief, and, relatedly, understanding of mind, exhibit genuine conceptual change in the preschool years.

  7. Experimental investigation of false positive errors in auditory species occurrence surveys

    USGS Publications Warehouse

    Miller, David A.W.; Weir, Linda A.; McClintock, Brett T.; Grant, Evan H. Campbell; Bailey, Larissa L.; Simons, Theodore R.

    2012-01-01

    False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine species occurrence. Our objectives were to characterize false positive error probabilities for auditory methods based on a large number of observers, to determine if targeted instruction could be used to reduce false positive error rates, and to establish useful predictors of among-observer and among-species differences in error rates. We recruited 31 observers, ranging in abilities from novice to expert, that recorded detections for 12 species during 180 calling trials (66,960 total observations). All observers made multiple false positive errors and on average 8.1% of recorded detections in the experiment were false positive errors. Additional instruction had only minor effects on error rates. After instruction, false positive error probabilities decreased by 16% for treatment individuals compared to controls with broad confidence interval overlap of 0 (95% CI: -46 to 30%). This coincided with an increase in false negative errors due to the treatment (26%; -3 to 61%). Differences among observers in false positive and in false negative error rates were best predicted by scores from an online test and a self-assessment of observer ability completed prior to the field experiment. In contrast, years of experience conducting call surveys was a weak predictor of error rates. False positive errors were also more common for species that were played more frequently, but were not related to the dominant spectral frequency of the call. Our results corroborate other work that demonstrates false positives are a significant component of species occurrence data collected by auditory

  8. Inflation after false vacuum decay: Observational prospects after Planck

    NASA Astrophysics Data System (ADS)

    Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo

    2015-04-01

    We assess two potential signals of the formation of our universe by the decay of a false vacuum. Negative spatial curvature is one possibility, but the window for its detection is now small. However, another possible signal is a suppression of the cosmic microwave background (CMB) power spectrum at large angles. This arises from the steepening of the effective potential as it interpolates between a flat inflationary plateau and the high barrier separating us from our parent vacuum. We demonstrate that these two effects can be parametrically separated in angular scale. Observationally, the steepening effect appears to be excluded at large ℓ; but it remains consistent with the slight lack of power below ℓ≈30 found by the WMAP and Planck collaborations. We give two simple models which improve the fit to the Planck data; one with observable curvature and one without. Despite cosmic variance, we argue that future CMB polarization and most importantly large-scale structure observations should be able to corroborate the Planck anomaly if it is real. If we further assume the specific theoretical setting of a landscape of metastable vacua, as suggested by string theory, we can estimate the probability of seeing a low-ℓ suppression in the CMB. There are significant theoretical uncertainties in such calculations, but we argue the probability for a detectable suppression may be as large as O (1 ), and in general is significantly larger than the probability of seeing curvature.

  9. Optimizing apparent display resolution enhancement for arbitrary videos.

    PubMed

    Stengel, Michael; Eisemann, Martin; Wenger, Stephan; Hell, Benjamin; Magnor, Marcus

    2013-09-01

    Display resolution is frequently exceeded by available image resolution. Recently, apparent display resolution enhancement (ADRE) techniques show how characteristics of the human visual system can be exploited to provide super-resolution on high refresh rate displays. In this paper, we address the problem of generalizing the ADRE technique to conventional videos of arbitrary content. We propose an optimization-based approach to continuously translate the video frames in such a way that the added motion enables apparent resolution enhancement for the salient image region. The optimization considers the optimal velocity, smoothness, and similarity to compute an appropriate trajectory. In addition, we provide an intuitive user interface that allows to guide the algorithm interactively and preserves important compositions within the video. We present a user study evaluating apparent rendering quality and show versatility of our method on a variety of general test scenes.

  10. Role of surface in apparent viscosity of glasses

    NASA Astrophysics Data System (ADS)

    Avramov, I.

    2014-03-01

    Two problems have intrigued experts for a long time: The one is within the context of the legend of flowing cathedral glass windows and the second is the inaccuracy appearing in very old thermometers of famous scientists. We relate this with the role of the surface on the apparent viscosity of glasses. The apparent viscosity could deviate from the bulk viscosity if the fraction w of the surface molecules, of small samples, is sufficiently large. The effect is more prominent at low temperatures, correspondingly at high viscosities. The interpretation is within the Avramov and Milchev viscosity model, combined with the predictions of the change of heat capacity for extremely small samples. We find that the apparent glass transition temperature could depend on the sample size, in agreement with experimental observations existing in the literature. In addition to glasses, the present results could be of importance for thin films and foams.

  11. Role of surface in apparent viscosity of glasses.

    PubMed

    Avramov, I

    2014-03-01

    Two problems have intrigued experts for a long time: The one is within the context of the legend of flowing cathedral glass windows and the second is the inaccuracy appearing in very old thermometers of famous scientists. We relate this with the role of the surface on the apparent viscosity of glasses. The apparent viscosity could deviate from the bulk viscosity if the fraction w of the surface molecules, of small samples, is sufficiently large. The effect is more prominent at low temperatures, correspondingly at high viscosities. The interpretation is within the Avramov and Milchev viscosity model, combined with the predictions of the change of heat capacity for extremely small samples. We find that the apparent glass transition temperature could depend on the sample size, in agreement with experimental observations existing in the literature. In addition to glasses, the present results could be of importance for thin films and foams.

  12. Doxylamine: a cause for false-positive gas chromatographic assay for phencyclidine.

    PubMed

    Schaldenbrand, J D; McClatchey, K D; Patel, J A; Muilenberg, M J

    1981-01-01

    A 25-year-old white woman ingested an unknown quantity of doxylamine succinate and flurazepam. Urine immunoassay screen (EMIT-dau) was positive for benzodiazopine and negative for phencyclidine. Subsequent gas chromatographic assay of the urine revealed a markedly positive assay for phencyclidine. Doxylamine was ultimately found to be the cause for the false-positive gas chromatographic assay for phencyclidine.

  13. Multiple-Choice and True/False Tests: Myths and Misapprehensions

    ERIC Educational Resources Information Center

    Burton, Richard F.

    2005-01-01

    Examiners seeking guidance on multiple-choice and true/false tests are likely to encounter various faulty or questionable ideas. Twelve of these are discussed in detail, having to do mainly with the effects on test reliability of test length, guessing and scoring method (i.e. number-right scoring or negative marking). Some misunderstandings could…

  14. Belief and sign, true and false: the unique of false belief reasoning.

    PubMed

    Zhang, Ting; Zhang, Qin; Li, Yiyuan; Long, Changquan; Li, Hong

    2013-11-01

    For a long time, a controversy has been proposed that whether the process of theory of mind is a result of domain-specific or domain-general changes (Wellman in The handbook of childhood cognitive development. Blackwell Publication, New Jersey, 2011). This event-related potential study explored the neural time course of domain-general and domain-specific components in belief reasoning. Fourteen participants completed location transfer false belief (FB), true belief (TB), false sign (FS) and true sign (TS) tasks, in which two pictures told a story related to a dog that ran from a green into a red box. In the TB and FB tasks, a boy saw or did not see the transfer of the dog, respectively. In the FS and TS tasks, an arrow that pointed to the green box either altered its direction to the red box or did not alter following the transfer of the dog. Participants then inferred where the boy thought of, or the arrow indicated the location of the dog. FB and TB reasoning elicited lower N2 amplitudes than FS and TS reasoning, which is associated with domain-general components, the detection, and classification. The late slow wave (LSW) for FB was more positive at frontal, central, and parietal sites than FS because of the domain-specific component involved in FB reasoning. However, the LSW was less positive for TB than for FB but did not differ from the TS condition, which implies that mental representation might not be involved in TB reasoning.

  15. Foliation dependence of black hole apparent horizons in spherical symmetry

    NASA Astrophysics Data System (ADS)

    Faraoni, Valerio; Ellis, George F. R.; Firouzjaee, Javad T.; Helou, Alexis; Musco, Ilia

    2017-01-01

    Numerical studies of gravitational collapse to black holes make use of apparent horizons, which are intrinsically foliation dependent. We expose the problem and discuss possible solutions using the Hawking-Hayward quasilocal mass. In spherical symmetry, we present a physically sensible approach to the problem by restricting to spherically symmetric spacetime slicings. In spherical symmetry, the apparent horizons enjoy a restricted gauge independence in any spherically symmetric foliation, but physical quantities associated with them, such as surface gravity and temperature, are fully gauge dependent. The widely used comoving and Kodama foliations, which are of particular interest, are discussed in detail as examples.

  16. A retrospective analysis of false-positive infectious screening results in blood donors

    PubMed Central

    Vo, Michelle T.; Bruhn, Roberta; Kaidarova, Zhanna; Custer, Brian S.; Murphy, Edward L.; Bloch, Evan M.

    2016-01-01

    BACKGROUND False-positive infectious transfusion screening results remain a challenge with continued loss of both donors and blood products. We sought to identify associations between donor demographic characteristics (age, race, sex, education, first-time donor status) and testing false positive for viruses during routine blood donation screening. In addition the study assessed the prevalence of high-risk behaviors in false-positive donors. STUDY DESIGN AND METHODS Blood Systems, Inc. donors with allogeneic donations between January 1, 2011, and December 31, 2012, were compared in a case-control study. Those with a false-positive donation for one of four viruses (human immunodeficiency virus [HIV], human T-lymphotropic virus [HTLV], hepatitis B virus [HBV], and hepatitis C virus [HCV]) were included as cases. Those with negative test results were controls. For a subset of cases, infectious risk factors were evaluated. RESULTS Black race and Hispanic ethnicity were associated with HCV and HTLV false-positive results. Male sex and lower education were associated with HCV false positivity, and age 25 to 44 was associated with HTLV false positivity. First-time donors were more likely to be HCV false positive although less likely to be HBV and HTLV false positive. No significant associations between donor demographics and HIV false positivity were observed. A questionnaire for false-positive donors showed low levels of high-risk behaviors. CONCLUSION Demographic associations with HCV and HTLV false-positive results overlap with those of true infection. While true infection is unlikely given current testing algorithms and risk factor evaluation, the findings suggest nonrandom association. Further investigation into biologic mechanisms is warranted. PMID:26509432

  17. The Rightful Role of MRI after Negative Conventional Imaging in the Management of Bloody Nipple Discharge.

    PubMed

    Sanders, Linda M; Daigle, Megan

    2016-01-01

    Nipple discharge is a frequent presenting complaint at breast clinics. Bloody nipple discharge (BND) has the highest risk of malignancy, albeit low. If mammogram and ultrasound are unrevealing, central duct excision (CDE) has been considered the gold standard in its management. Magnetic resonance imaging (MRI) has been widely confirmed as a highly sensitive test for detection of breast cancer, with an accompanying high negative predictive value. This article presents a retrospective review of patients with BND and negative conventional imaging, comparing outcome of patients who went directly to CDE without MRI to those patients who underwent preoperative MRI. Of 115 patients who underwent mammography and US alone prior to CDE, eight cancers were detected (seven ductal carcinoma in situ [DCIS] and 1 IDC, 7 mm [T1b]; incidence: 7%). Of 85 patients who underwent conventional imaging followed by MRI prior to surgery, eight cancers were detected (all DCIS; incidence: 9.4%), seven of which were identified by MRI. The one false-negative MRI had subtle findings which, in retrospect, were misinterpreted; however, a clinically apparent nipple lesion prompted surgical biopsy. Of 56 patients with a negative or benign MRI, CDE was negative for malignancy in all but that one patient. Sensitivity and specificity were 87.5%/71.4%. Positive predictive value and negative predictive value (NPV) were 24.1%/98.2%. MRI should be performed in all patients with BND and negative conventional imaging. The extremely high NPV of MRI suggests that a negative study could obviate CDE in most patients unless overriding clinical factors prevail.

  18. Apparent competition in canopy trees determined by pathogen transmission rather than susceptibility.

    PubMed

    Cobb, Richard C; Meentemeyer, Ross K; Rizzo, David M

    2010-02-01

    Epidemiological theory predicts that asymmetric transmission, susceptibility, and mortality within a community will drive pathogen and disease dynamics. These epidemiological asymmetries can result in apparent competition, where a highly infectious host reduces the abundance of less infectious or more susceptible members in a community via a shared pathogen. We show that the exotic pathogen Phytophthora ramorum and resulting disease, sudden oak death, cause apparent competition among canopy trees and that transmission differences among canopy trees drives patterns of disease severity in California coast redwood forests. P. ramorum ranges in its ability to infect, sporulate on, and cause mortality of infected hosts. A path analysis showed that the most prolific inoculum producer, California bay laurel (Umbellularia californica), had a greater impact on the mortality rate of tanoak (Lithocarpus densiflorus) than did other inoculum-supporting species. In stands experiencing high tanoak mortality, lack of negative impacts by P. ramorum on bay laurel may increase bay laurel density and subsequently result in positive feedback on pathogen populations. This study demonstrates the degree to which invasive, generalist pathogens can cause rapid changes in forest canopy composition and that differences in transmission can be more important than susceptibility in driving patterns of apparent competition.

  19. Dissociated developmental trajectories for semantic and phonological false memories.

    PubMed

    Holliday, Robyn E; Weekes, Brendan S

    2006-07-01

    False recognition following presentation of semantically related and phonologically related word lists was evaluated in 8-, 11-, and 13-year-olds. Children heard lists of words that were either semantic (e.g., bed, rest, wake ...) or phonological associates (e.g., pole, bowl, hole ...) of a critical unpresented word (e.g., sleep, roll), respectively. A semantic false memory was defined as false recognition of a semantically related but unpresented word. A phonological false memory was defined as false recognition of a phonologically related but unpresented word. False memories in the two tasks showed opposite developmental trends, increasing with age for semantic relatedness and decreasing with age for phonological relatedness.

  20. Decoy Methods for Assessing False Positives and False Discovery Rates in Shotgun Proteomics

    PubMed Central

    Wang, Guanghui; Wu, Wells W.; Zhang, Zheng; Masilamani, Shyama; Shen, Rong-Fong

    2008-01-01

    The potential of getting a significant number of false positives (FPs) in peptide-spectrum matches (PSMs) obtained by proteomic database search has been well-recognized. Among the attempts to assess FPs, the concomitant use of target and decoy databases is widely practiced. By adjusting filtering criteria, FPs and false discovery rate (FDR) can be controlled at a desired level. Although the target-decoy approach is gaining in popularity, subtle differences in decoy construction (e.g., reversing vs. stochastic methods), rate calculation (e.g., total vs. unique PSMs), or searching (separate vs. composite) do exist among various implementations. In the present study, we evaluated the effects of these differences on FP and FDR estimations using a rat kidney protein sample and the SEQUEST search engine as an example. On the effects of decoy construction, we found that, when a single scoring filter (XCorr) was used, stochastic methods generated a higher estimation of FPs and FDR than sequence reversing methods, likely due to an increase in unique peptides. This higher estimation could largely be attenuated by creating decoy databases similar in effective size, but not by a simple normalization with a unique-peptide coefficient. When multiple filters were applied, the differences seen between reversing and stochastic methods significantly diminished, suggesting multiple filterings reduce the dependency on how a decoy is constructed. For a fixed set of filtering criteria, FDR and FPs estimated by using unique PSMs were almost twice those using total PSMs. The higher estimation seemed to be dependent on data acquisition setup. As to the differences between performing separate or composite searches, in general, FDR estimated from separate search was about three times that from composite search. The degree of difference gradually decreased as the filtering criteria became more stringent. Paradoxically, the estimated true positives in separate search were higher when multiple

  1. Apparent horizons in D-dimensional Robinson-Trautman spacetime

    SciTech Connect

    Svitek, Otakar

    2009-05-01

    We derive the higher dimensional generalization of Penrose-Tod equation describing apparent horizons in Robinson-Trautman spacetimes. New results concerning the existence and uniqueness of its solutions in four dimensions are proven. Namely, previous results of Tod [1] are generalized to nonvanishing cosmological constant.

  2. Independent Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.; Vrastil, J.; Williams, S. C.; Henze, M.; Meusinger, H.; Pohl, C.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.

    2017-02-01

    The M81 nova monitoring collaboration reports the independent discovery of an apparent nova in M81 on a co-added 3510-s unfiltered CCD frame taken on 2017 Feb. 24.119 UT with the 0.65-m telescope at Ondrejov.

  3. Independent Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.; Williams, S. C.; Henze, M.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.; Meusinger, H.

    2017-02-01

    The M81 nova monitoring collaboration reports the independent discovery of an apparent nova in M81 on a co-added 5400-s unfiltered CCD frame taken on 2017 Feb. 19.962 UT with the 0.65-m telescope at Ondrejov (OND).

  4. An Apparent Paradox: Catt's Anomaly

    ERIC Educational Resources Information Center

    Pieraccini, M.; Selleri, S.

    2013-01-01

    Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

  5. Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Alfaro, M. Diaz; Ordonez-Etxeberria, I.; Vaduvescu, O.

    2015-01-01

    We report the discovery of an apparent nova in M81 on a co-added 1600-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~2.4" seeing on 2015 Jan. 15.126 UT.

  6. Apparent digestible energy value of crude glycerol fed to pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The apparent digestible energy of crude glycerol, a co-product of biodiesel production, was determined in two studies conducted at the Iowa State University Swine Nutrition Research Farm, Ames, IA. In the first study, 24 barrows with an average body weight of 11.0 kg were fed 376 g/d of a basal corn...

  7. A New Theory of Leadership: "Realwert" Versus Apparent Good.

    ERIC Educational Resources Information Center

    Lang, Donald

    1999-01-01

    "Realwert" ("real good") stems from an understanding of humanity's "raison d'etre"--treating others with respect and dignity. It can be contrasted with "apparent good," a condition wherein one mistakenly thinks real good is being pursued. Drawing on Aquinas and Hodginson, this paper argues for a…

  8. Changes in apparent duration follow shifts in perceptual timing

    PubMed Central

    Bruno, Aurelio; Ayhan, Inci; Johnston, Alan

    2015-01-01

    It is well established that the apparent duration of moving visual objects is greater at higher as compared to slower speeds. Here we report the effects of acceleration and deceleration on the perceived duration of a drifting grating with average speed kept constant (10°/s).For acceleration, increasing the speed range progressively reduced perceived duration. The magnitude of apparent duration compression was determined by speed rather than temporal frequency and was proportional to speed range (independent of standard duration) rather than acceleration. The perceived duration reduction was also proportional to the standard length. The effects of increases and decreases in speed were highly asymmetric. Reducing speed through the interval induced a moderate increase in perceived duration. These results could not be explained by changes in apparent onset or offset or differences in perceived average speed between intervals containing increasing speed and intervals containing decreasing speed. Paradoxically, for intervals combining increasing speed and decreasing speed, compression only occurred when increasing speed occurred in the second half of the interval. We show that this pattern of results in the duration domain was concomitant with changes in the reported direction of apparent motion of Gaussian blobs, embedded in intervals of increasing or decreasing speed, that could be predicted from adaptive changes in the temporal impulse response function. We detected similar changes after flicker adaptation, suggesting that the two effects might be linked through changes in the temporal tuning of visual filters. PMID:26024450

  9. Effects of hydrocortisone on false memory recognition in healthy men and women.

    PubMed

    Duesenberg, Moritz; Weber, Juliane; Schaeuffele, Carmen; Fleischer, Juliane; Hellmann-Regen, Julian; Roepke, Stefan; Moritz, Steffen; Otte, Christian; Wingenfeld, Katja

    2016-12-01

    Most of the studies focusing on the effect of stress on false memories by using psychosocial and physiological stressors yielded diverse results. In the present study, we systematically tested the effect of exogenous hydrocortisone using a false memory paradigm. In this placebo-controlled study, 37 healthy men and 38 healthy women (mean age 24.59 years) received either 10 mg of hydrocortisone or placebo 75 min before using the false memory, that is, Deese-Roediger-McDermott (DRM), paradigm. We used emotionally charged and neutral DRM-based word lists to look for false recognition rates in comparison to true recognition rates. Overall, we expected an increase in false memory after hydrocortisone compared to placebo. No differences between the cortisol and the placebo group were revealed for false and for true recognition performance. In general, false recognition rates were lower compared to true recognition rates. Furthermore, we found a valence effect (neutral, positive, negative, disgust word stimuli), indicating higher rates of true and false recognition for emotional compared to neutral words. We further found an interaction effect between sex and recognition. Post hoc t tests showed that for true recognition women showed a significantly better memory performance than men, independent of treatment. This study does not support the hypothesis that cortisol decreases the ability to distinguish between old versus novel words in young healthy individuals. However, sex and emotional valence of word stimuli appear to be important moderators. (PsycINFO Database Record

  10. Telling true from false: cannabis users show increased susceptibility to false memories.

    PubMed

    Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A

    2015-06-01

    Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring.

  11. Telling true from false: cannabis users show increased susceptibility to false memories

    PubMed Central

    Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A

    2015-01-01

    Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring. PMID:25824306

  12. False alarms: How early warning signals falsely predict abrupt sea ice loss

    NASA Astrophysics Data System (ADS)

    Wagner, Till J. W.; Eisenman, Ian

    2015-12-01

    Uncovering universal early warning signals for critical transitions has become a coveted goal in diverse scientific disciplines, ranging from climate science to financial mathematics. There has been a flurry of recent research proposing such signals, with increasing autocorrelation and increasing variance being among the most widely discussed candidates. A number of studies have suggested that increasing autocorrelation alone may suffice to signal an impending transition, although some others have questioned this. Here we consider variance and autocorrelation in the context of sea ice loss in an idealized model of the global climate system. The model features no bifurcation, nor increased rate of retreat, as the ice disappears. Nonetheless, the autocorrelation of summer sea ice area is found to increase in a global warming scenario. The variance, by contrast, decreases. A simple physical mechanism is proposed to explain the occurrence of increasing autocorrelation but not variance when there is no approaching bifurcation. Additionally, a similar mechanism is shown to allow an increase in both indicators with no physically attainable bifurcation. This implies that relying on autocorrelation and variance as early warning signals can raise false alarms in the climate system, warning of "tipping points" that are not actually there.

  13. Rethinking the Relationship between Social Experience and False-Belief Understanding: A Mentalistic Account

    PubMed Central

    Roby, Erin; Scott, Rose M.

    2016-01-01

    It was long assumed that the capacity to represent false beliefs did not emerge until at least age four, as evidenced by children’s performance on elicited-response tasks. However, recent evidence that infants appear to demonstrate false-belief understanding when tested with alternative, non-elicited-response measures has led some researchers to conclude that the capacity to represent beliefs emerges in the 1st year of life. This mentalistic view has been criticized for failing to offer an explanation for the well-established positive associations between social factors and preschoolers’ performance on elicited-response false-belief tasks. In this paper, we address this criticism by offering an account that reconciles these associations with the mentalistic claim that false-belief understanding emerges in infancy. We propose that rather than facilitating the emergence of the capacity to represent beliefs, social factors facilitate the use of this ability via effects on attention, inference, retrieval, and response production. Our account predicts that the relationship between social factors and false-belief understanding should not be specific to preschoolers’ performance in elicited-response tasks: this relationship should be apparent across the lifespan in a variety of paradigms. We review an accumulating body of evidence that supports this prediction. PMID:27857702

  14. Emotionally negative pictures enhance gist memory.

    PubMed

    Bookbinder, S H; Brainerd, C J

    2017-02-01

    In prior work on how true and false memory are influenced by emotion, valence and arousal have often been conflated. Thus, it is difficult to say which specific effects are caused by valence and which are caused by arousal. In the present research, we used a picture-memory paradigm that allowed emotional valence to be manipulated with arousal held constant. Negatively valenced pictures elevated both true and false memory, relative to positive and neutral pictures. Conjoint recognition modeling revealed that negative valence (a) reduced erroneous suppression of true memories and (b) increased the familiarity of the semantic content of both true and false memories. Overall, negative valence impaired the verbatim side of episodic memory but enhanced the gist side, and these effects persisted even after a week-long delay. (PsycINFO Database Record

  15. Chinese Preschoolers' Implicit and Explicit False-Belief Understanding

    ERIC Educational Resources Information Center

    Wang, Bo; Low, Jason; Jing, Zhang; Qinghua, Qu

    2012-01-01

    Mandarin-speaking preschoolers in Mainland China (3- to 4-year-olds; N = 192) were tested for dissociations between anticipatory looking (AL) and verbal judgments on false-belief tasks. The dissociation between the two kinds of understanding was robust despite direct false-belief test questions using a Mandarin specific think-falsely verb and…

  16. The Strategic Nature of False Recognition in the DRM Paradigm

    ERIC Educational Resources Information Center

    Miller, Michael B.; Guerin, Scott A.; Wolford, George L.

    2011-01-01

    The false memory effect produced by the Deese/Roediger & McDermott (DRM) paradigm is reportedly impervious to warnings to avoid false alarming to the critical lures (D. A. Gallo, H. L. Roediger III, & K. B. McDermott, 2001). This finding has been used as strong evidence against models that attribute the false alarms to a decision…

  17. Lexical Association and False Memory for Words in Two Cultures

    ERIC Educational Resources Information Center

    Lee, Yuh-Shiow; Chiang, Wen-Chi; Hung, Hsu-Ching

    2008-01-01

    This study examined the relationship between language experience and false memory produced by the DRM paradigm. The word lists used in Stadler, et al. (Memory & Cognition, 27, 494-500, 1999) were first translated into Chinese. False recall and false recognition for critical non-presented targets were then tested on a group of Chinese users.…

  18. Compelling Untruths: Content Borrowing and Vivid False Memories

    ERIC Educational Resources Information Center

    Lampinen, James Michael; Meier, Christopher R.; Arnal, Jack D.; Leding, Juliana K.

    2005-01-01

    False memories are sometimes accompanied by surprisingly vivid experiential detail that makes them difficult to distinguish from actual memories. Such strikingly real false memories may be produced by a process called content borrowing in which details from presented items are errantly borrowed to corroborate the occurrence of the false memory…

  19. 75 FR 2853 - False Killer Whale Take Reduction Team Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... National Oceanic and Atmospheric Administration RIN 0648-XT76 False Killer Whale Take Reduction Team... (NOAA), Department of Commerce. ACTION: Notice of establishment of a False Killer Whale Take Reduction... Insular, and Palmyra Atoll stocks of false killer whales (Pseudorca crassidens) in the Hawaii-based...

  20. False-positive cancer screens and health-related quality of life.

    PubMed

    McGovern, Patricia M; Gross, Cynthia R; Krueger, Richard A; Engelhard, Deborah A; Cordes, Jill E; Church, Timothy R

    2004-01-01

    By design, screening tests are imperfect-unresponsive to some cancers (false negatives) while occasionally raising suspicion of cancer where none exists (false positives). This pilot study describes patients' responses to having a false-positive screening test for cancer, and identifies screening effects on health-related quality of life (HRQoL). The pilot findings suggest issues important for incorporation in future evaluations of the impact of screening for prostate, lung, colon, or ovarian (PLCO) cancers. Seven focus groups were conducted to identify the nature and meaning of all phases of PLCO screening. Minnesota participants in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial who had completed screening, with at least 1 false-positive screen, participated (N = 47). Participants' reactions to abnormal screens and diagnostic work-ups were primarily emotional (eg, anxiety and distress), not physical, and ultimately positive for the majority. Health distress and fear of cancer and death were the major negative aspects of HRQoL identified. These concepts are not typically included in generic HRQoL questionnaires like the SF-36, but are highly relevant to PLCO screening. Clinicians were regarded as underestimating the discomfort of follow-up diagnostic testing. However, relief and assurance appeared to eventually outweigh the negative emotions for most participants. Implications for oncology nurses include the need to consider the emotional consequences of screening in association with screen reliability and validity.

  1. The effect of mood on false memory for emotional DRM word lists.

    PubMed

    Zhang, Weiwei; Gross, Julien; Hayne, Harlene

    2017-04-01

    In the present study, we investigated the effect of participants' mood on true and false memories of emotional word lists in the Deese-Roediger-McDermott (DRM) paradigm. In Experiment 1, we constructed DRM word lists in which all the studied words and corresponding critical lures reflected a specified emotional valence. In Experiment 2, we used these lists to assess mood-congruent true and false memory. Participants were randomly assigned to one of three induced-mood conditions (positive, negative, or neutral) and were presented with word lists comprised of positive, negative, or neutral words. For both true and false memory, there was a mood-congruent effect in the negative mood condition; this effect was due to a decrease in true and false recognition of the positive and neutral words. These findings are consistent with both spreading-activation and fuzzy-trace theories of DRM performance and have practical implications for our understanding of the effect of mood on memory.

  2. Arousal-But Not Valence-Reduces False Memories at Retrieval.

    PubMed

    Mirandola, Chiara; Toffalini, Enrico

    2016-01-01

    Mood affects both memory accuracy and memory distortions. However, some aspects of this relation are still poorly understood: (1) whether valence and arousal equally affect false memory production, and (2) whether retrieval-related processes matter; the extant literature typically shows that mood influences memory performance when it is induced before encoding, leaving unsolved whether mood induced before retrieval also impacts memory. We examined how negative, positive, and neutral mood induced before retrieval affected inferential false memories and related subjective memory experiences. A recognition-memory paradigm for photographs depicting script-like events was employed. Results showed that individuals in both negative and positive moods-similar in arousal levels-correctly recognized more target events and endorsed fewer false memories (and these errors were linked to remember responses less frequently), compared to individuals in neutral mood. This suggests that arousal (but not valence) predicted memory performance; furthermore, we found that arousal ratings provided by participants were more adequate predictors of memory performance than their actual belonging to either positive, negative or neutral mood groups. These findings suggest that arousal has a primary role in affecting memory, and that mood exerts its power on true and false memory even when induced at retrieval.

  3. Arousal—But Not Valence—Reduces False Memories at Retrieval

    PubMed Central

    Mirandola, Chiara; Toffalini, Enrico

    2016-01-01

    Mood affects both memory accuracy and memory distortions. However, some aspects of this relation are still poorly understood: (1) whether valence and arousal equally affect false memory production, and (2) whether retrieval-related processes matter; the extant literature typically shows that mood influences memory performance when it is induced before encoding, leaving unsolved whether mood induced before retrieval also impacts memory. We examined how negative, positive, and neutral mood induced before retrieval affected inferential false memories and related subjective memory experiences. A recognition-memory paradigm for photographs depicting script-like events was employed. Results showed that individuals in both negative and positive moods–similar in arousal levels–correctly recognized more target events and endorsed fewer false memories (and these errors were linked to remember responses less frequently), compared to individuals in neutral mood. This suggests that arousal (but not valence) predicted memory performance; furthermore, we found that arousal ratings provided by participants were more adequate predictors of memory performance than their actual belonging to either positive, negative or neutral mood groups. These findings suggest that arousal has a primary role in affecting memory, and that mood exerts its power on true and false memory even when induced at retrieval. PMID:26938737

  4. Culture-negative endocarditis

    MedlinePlus

    ... inflammation of the lining of one or more heart valves, but no endocarditis-causing germs can be found ... the heart, where they can settle on damaged heart valves. Alternative Names Endocarditis (culture-negative) Images Culture-negative ...

  5. False Memories for Suggestions: The Impact of Conceptual Elaboration.

    PubMed

    Zaragoza, Maria S; Mitchell, Karen J; Payment, Kristie; Drivdahl, Sarah

    2011-01-01

    Relatively little attention has been paid to the potential role that reflecting on the meaning and implications of suggested events (i.e., conceptual elaboration) might play in promoting the creation of false memories. Two experiments assessed whether encouraging repeated conceptual elaboration, would, like perceptual elaboration, increase false memory for suggested events. Results showed that conceptual elaboration of suggested events more often resulted in high confidence false memories (Experiment 1) and false memories that were accompanied by the phenomenal experience of remembering them (Experiment 2) than did surface-level processing. Moreover, conceptual elaboration consistently led to higher rates of false memory than did perceptual elaboration. The false memory effects that resulted from conceptual elaboration were highly dependent on the organization of the postevent interview questions, such that conceptual elaboration only increased false memory beyond surface level processing when participants evaluated both true and suggested information in relation to the same theme or dimension.

  6. Warnings reduce false memories for missing aspects of events.

    PubMed

    Gerrie, Matthew P; Garry, Maryanne

    2011-01-01

    When people see movies with some parts missing, they falsely recognize many of the missing parts later. In two experiments, we examined the effect of warnings on people's false memories for these parts. In Experiment 1, warning subjects about false recognition before the movie (forewarnings) reduced false recognition, but warning them after the movie (postwarnings) reduced false recognition to a lesser extent. In Experiment 2, the effect of the warnings depended on the nature of the missing parts. Forewarnings were more effective than postwarnings in reducing false recognition of missing noncrucial parts, but forewarnings and postwarnings were similarly effective in reducing false recognition of crucial missing parts. We use the source monitoring framework to explain our results.

  7. Wavelength dependence of the apparent diameter of retinal blood vessels

    NASA Astrophysics Data System (ADS)

    Park, Robert; Twietmeyer, Karen; Chipman, Russell; Beaudry, Neil; Salyer, David

    2005-04-01

    Imaging of retinal blood vessels may assist in the diagnosis and monitoring of diseases such as glaucoma, diabetic retinopathy, and hypertension. However, close examination reveals that the contrast and apparent diameter of vessels are dependent on the wavelength of the illuminating light. In this study multispectral images of large arteries and veins within enucleated swine eyes are obtained with a modified fundus camera by use of intravitreal illumination. The diameters of selected vessels are measured as a function of wavelength by cross-sectional analysis. A fixed scale with spectrally independent dimension is placed above the retina to isolate the chromatic effects of the imaging system and eye. Significant apparent differences between arterial and venous diameters are found, with larger diameters observed at shorter wavelengths. These differences are due primarily to spectral absorption in the cylindrical blood column.

  8. On the apparent molar volumes of nonelectrolytes in water

    SciTech Connect

    Anderko, A.; Chan, J.P.; Pitzer, K.S. )

    1993-04-01

    Apparent molar volumes of aqueous solutions of argon and xenon have been calculated using a previously developed comprehensive equation of state for nonelectrolyte systems. The equation consists of a virial expansion truncated after the fourth virial coefficient and a closed-form term approximating higher coefficients. Mixing rules are based on the composition dependence of virial coefficients, which is known from statistical mechanics. The equation accurately represents vapor-liquid and gas-gas equilibria for the Ar + H[sub 2]O and Xe + H[sub 2]O systems over wide ranges of pressure and temperature using two binary parameters. With the binary parameters determined from phase equilibrium data, the equation accurately predicts apparent molar volumes V[sub [phi

  9. Apparent motion enhances visual rhythm discrimination in infancy.

    PubMed

    Brandon, Melissa; Saffran, Jenny R

    2011-05-01

    Many studies have demonstrated that infants exhibit robust auditory rhythm discrimination, but research on infants' perception of visual rhythm is limited. In particular, the role of motion in infants' perception of visual rhythm remains unknown, despite the prevalence of motion cues in naturally occurring visual rhythms. In the present study, we examined the role of motion in 7-month-old infants' discrimination of visual rhythms by comparing experimental conditions with apparent motion in the stimuli versus stationary rhythmic stimuli. Infants succeeded at discriminating visual rhythms only when the visual rhythm occurred with an apparent motion component. These results support the view that motion plays a role in infants' perception of visual temporal information, consistent with the manner in which natural rhythms appear in the visual world.

  10. Negative ion generator

    DOEpatents

    Stinnett, Regan W.

    1984-01-01

    A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions.

  11. Negative ion generator

    DOEpatents

    Stinnett, R.W.

    1984-05-08

    A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions. 8 figs.

  12. Apparent optical density of the scattering medium: influence of scattering

    NASA Astrophysics Data System (ADS)

    Kiseleva, Irina A.; Sinichkin, Yurii P.

    2002-07-01

    Comparative analysis of manifestation of finite absorption in scattering media is carried out for different detection geometries. Reflectance spectra were studied for phantom scattering media containing blood and melanin as absorbers. Apparent optical density spectra of phantom media are compared with similar spectra of water solutions of the blood and melanin for same concentrations of absorbers. The influence of scattering properties on optical density spectra is discussed with use of the model of diffuse light propagation in semi-infinite media.

  13. Apparent Explosion Moments from Rg Waves Recorded on SPE

    DOE PAGES

    Larmat, Carene; Rougier, Esteban; Patton, Howard John

    2016-11-29

    Seismic moments for the first four chemical tests making up phase I of the Source Physics Experiments (SPE) are estimated from 6-Hz Rg waves recorded along a single radial line of geophones under the assumption that the tests are pure explosions. These apparent explosion moments are compared with moments determined from the reduced displacement potential method applied to free-field data. Light detection and ranging (lidar) observations, strong ground motions on the free surface in the vicinity of ground zero, and moment tensor inversion results are evidence that the fourth test SPE-4P is a pure explosion, and the moments show goodmore » agreement, 8×1010 N·m for free-field data versus 9×1010 N·m for Rg waves. In stark contrast, apparent moments for the first three tests are smaller than near-field moments by factors of 3–4. Relative amplitudes for the three tests determined from Rg interferometry using SPE-4P as an empirical Green’s function indicate that radiation patterns are cylindrically symmetric within a factor of 1.25 (25%). This fact assures that the apparent moments are reliable even though they were measured on just one azimuth. Spallation occurred on the first three tests, and ground-based lidar detected permanent deformations. As such, the source medium suffered late-time damage. In conclusion, destructive interference between Rg waves radiated by explosion and damage sources will reduce amplitudes and explain why apparent moments are smaller than near-field moments based on compressional energy emitted directly from the source.« less

  14. Apparent Explosion Moments from Rg Waves Recorded on SPE

    SciTech Connect

    Larmat, Carene; Rougier, Esteban; Patton, Howard John

    2016-11-29

    Seismic moments for the first four chemical tests making up phase I of the Source Physics Experiments (SPE) are estimated from 6-Hz Rg waves recorded along a single radial line of geophones under the assumption that the tests are pure explosions. These apparent explosion moments are compared with moments determined from the reduced displacement potential method applied to free-field data. Light detection and ranging (lidar) observations, strong ground motions on the free surface in the vicinity of ground zero, and moment tensor inversion results are evidence that the fourth test SPE-4P is a pure explosion, and the moments show good agreement, 8×1010 N·m for free-field data versus 9×1010 N·m for Rg waves. In stark contrast, apparent moments for the first three tests are smaller than near-field moments by factors of 3–4. Relative amplitudes for the three tests determined from Rg interferometry using SPE-4P as an empirical Green’s function indicate that radiation patterns are cylindrically symmetric within a factor of 1.25 (25%). This fact assures that the apparent moments are reliable even though they were measured on just one azimuth. Spallation occurred on the first three tests, and ground-based lidar detected permanent deformations. As such, the source medium suffered late-time damage. In conclusion, destructive interference between Rg waves radiated by explosion and damage sources will reduce amplitudes and explain why apparent moments are smaller than near-field moments based on compressional energy emitted directly from the source.

  15. Mass density at geostationary orbit and apparent mass refilling

    NASA Astrophysics Data System (ADS)

    Denton, R. E.; Takahashi, Kazue; Amoh, Justice; Singer, H. J.

    2016-04-01

    We used the inferred equatorial mass density ρm,eq based on measurements of Alfvén wave frequencies measured by the GOES satellites during 1980-1991 in order to construct a number of different models of varying complexity for the equatorial mass density at geostationary orbit. The most complicated models are able to account for 66% of the variance with a typical variation from actual values of a factor of 1.56. The factors that influenced ρm,eq in the models were, in order of decreasing importance, the F10.7 EUV index, magnetic local time, the solar wind dynamic pressure Pdyn, the phase of the year, and the solar wind BZ (GSM Z direction). During some intervals, some of which were especially geomagnetically quiet, ρm,eq rose to values that were significantly higher than those predicted by our models. For 10 especially quiet intervals, we examined long-term (>1 day) apparent refilling, the increase in ρm,eq at a fixed location. We found that the behavior of ρm,eq varies for different events. In some cases, there is significant apparent refilling, whereas in other cases ρm,eq stays the same or even decreases slightly. Nevertheless, we showed that on average, ρm,eq increases exponentially during quiet intervals. There is variation of apparent refilling with respect to the phase of the solar cycle. On the third day of apparent refilling, ρm,eq has on average a similar value at solar maximum or solar minimum, but at solar maximum, ρm,eq begins with a larger value and rises relatively less than at solar minimum.

  16. The False Memory and the Mirror Effects: The Role of Familiarity and Backward Association in Creating False Recollections

    ERIC Educational Resources Information Center

    Anaki, D.; Faran, Y.; Ben-Shalom, D.; Henik, A.

    2005-01-01

    The mirror effect refers to a phenomenon where the hit rate is higher for low frequency words while the false alarm rate is higher for high frequency distractors. Using a false memory paradigm (Roediger & McDermott, 1995), we examined whether false memory for non-presented lures would be influenced by the lure's familiarity. The results revealed…

  17. Sentential Negation in English

    ERIC Educational Resources Information Center

    Mowarin, Macaulay

    2009-01-01

    This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

  18. Apparent competition with an exotic plant reduces native plant establishment.

    PubMed

    Orrock, John L; Witter, Martha S; Reichman, O J

    2008-04-01

    Biological invasions can change ecosystem function, have tremendous economic costs, and impact human health; understanding the forces that cause and maintain biological invasions is thus of immediate importance. A mechanism by which exotic plants might displace native plants is by increasing the pressure of native consumers on native plants, a form of indirect interaction termed "apparent competition." Using experimental exclosures, seed addition, and monitoring of small mammals in a California grassland, we examined whether exotic Brassica nigra increases the pressure of native consumers on a native bunchgrass, Nassella pulchra. Experimental plots were weeded to focus entirely on indirect effects via consumers. We demonstrate that B. nigra alters the activity of native small-mammal consumers, creating a gradient of consumption that dramatically reduces N. pulchra establishment. Previous work has shown that N. pulchra is a strong competitor, but that it is heavily seed limited. By demonstrating that consumer pressure is sufficient to curtail establishment, our work provides a mechanism for this seed limitation and suggests that, despite being a good competitor, N. pulchra cannot reestablish close to B. nigra within its old habitats because exotic-mediated consumption preempts direct competitive exclusion. Moreover, we find that apparent competition has a spatial extent, suggesting that consumers may dictate the rate of invasion and the area available for restoration, and that nonspatial studies of apparent competition may miss important dynamics.

  19. Coherent and random apparent stresses in periodically unsteady flows

    NASA Astrophysics Data System (ADS)

    Kehoe, Anthony Byrd

    1990-08-01

    The transitional flow field downstream of a smooth, symmetrically constricted Sylgard pipe was measured with a two color, two component Laser Doppler Anemometer for both pulsatile and steady flows. Vibrations in the flow system were induced with an exciter/shaker and were monitored with an accelerator. The vibration has little effect on the value of the maximum axial and radial turbulence intensities. A frequency domain signal processing technique to separate the disturbance velocity into coherent and random components was modified to guarantee that the sum of the decomposed velocity components equaled the original disturbance velocity. Results of the velocity separation demonstrated that the velocity disturbances prior to turbulent transition consisted almost entirely of coherent velocity fluctuations. The maximum apparent shear stress was found to occur just after the turbulent transition and consisted almost entirely of the random component. The data suggest that if the absolute magnitude of the apparent stress is the determining factor in red blood cell destruction, then the coherent apparent stress is not a significant destruction mechanism. However, the exact mechanism in hemolysis are not identified.

  20. Product design enhancement using apparent usability and affective quality.

    PubMed

    Seva, Rosemary R; Gosiaco, Katherine Grace T; Santos, Ma Crea Eurice D; Pangilinan, Denise Mae L

    2011-03-01

    In this study, apparent usability and affective quality were integrated in a design framework called the Usability Perception and Emotion Enhancement Model (UPEEM). The UPEEM was validated using structural equation modeling (SEM). The methodology consists of four phases namely product selection, attribute identification, design alternative generation, and design alternative evaluation. The first stage involved the selection of a product that highly involves the consumer. In the attribute identification stage, design elements of the product were identified. The possible values of these elements were also determined for use in the experimentation process. Design of experiments was used to identify how the attributes will be varied in the design alternative stage and which of the attributes significantly contribute to affective quality, apparent usability, and desirability in the design evaluation stage. Results suggest that product attributes related to form are relevant in eliciting intense affect and perception of usability in mobile phones especially those directly related to functionality and aesthetics. This study considered only four product attributes among so many due to the constraints of the research design employed. Attributes related to aesthetic perception of a product enhance apparent usability such as those related to dimensional ratios.

  1. Developmental Reversals in False Memory: Effects of Emotional Valence and Arousal

    PubMed Central

    Brainerd, C. J.; Holliday, R. E.; Reyna, V. F.; Yang, Y.; Toglia, M. P.

    2010-01-01

    Do the emotional valence and arousal of events distort children’s memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can be manipulated factorially. False memories increased with age for unpresented semantic associates of word lists, and net accuracy (the ratio of true memory to total memory) decreased with age. These surprising developmental trends were more pronounced for negatively-valenced materials than for positively-valenced materials, they were more pronounced for high-arousal materials than for low-arousal materials, and developmental increases in the effects of arousal were small in comparison to developmental increases in the effects of valence. These findings have ramifications for legal applications of false-memory research: Materials that share the emotional hallmark of crimes (events that are negatively valenced and arousing) produced the largest age increases in false memory and the largest age declines in net accuracy. PMID:20547393

  2. Developmental reversals in false memory: Effects of emotional valence and arousal.

    PubMed

    Brainerd, C J; Holliday, R E; Reyna, V F; Yang, Y; Toglia, M P

    2010-10-01

    Do the emotional valence and arousal of events distort children's memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can be manipulated factorially. False memories increased with age for unpresented semantic associates of word lists, and net accuracy (the ratio of true memory to total memory) decreased with age. These surprising developmental trends were more pronounced for negatively valenced materials than for positively valenced materials, they were more pronounced for high-arousal materials than for low-arousal materials, and developmental increases in the effects of arousal were small in comparison with developmental increases in the effects of valence. These findings have ramifications for legal applications of false memory research; materials that share the emotional hallmark of crimes (events that are negatively valenced and arousing) produced the largest age increases in false memory and the largest age declines in net accuracy.

  3. Serotonin, Inhibition, and Negative Mood

    PubMed Central

    Dayan, Peter; Huys, Quentin J. M

    2008-01-01

    Pavlovian predictions of future aversive outcomes lead to behavioral inhibition, suppression, and withdrawal. There is considerable evidence for the involvement of serotonin in both the learning of these predictions and the inhibitory consequences that ensue, although less for a causal relationship between the two. In the context of a highly simplified model of chains of affectively charged thoughts, we interpret the combined effects of serotonin in terms of pruning a tree of possible decisions, (i.e., eliminating those choices that have low or negative expected outcomes). We show how a drop in behavioral inhibition, putatively resulting from an experimentally or psychiatrically influenced drop in serotonin, could result in unexpectedly large negative prediction errors and a significant aversive shift in reinforcement statistics. We suggest an interpretation of this finding that helps dissolve the apparent contradiction between the fact that inhibition of serotonin reuptake is the first-line treatment of depression, although serotonin itself is most strongly linked with aversive rather than appetitive outcomes and predictions. PMID:18248087

  4. 15 CFR 930.35 - Negative determinations for proposed activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Negative determinations for proposed... Federal Agency Activities § 930.35 Negative determinations for proposed activities. (a) If a Federal... agencies with a negative determination for a Federal agency activity: (1) Identified by a State agency...

  5. 21 CFR 868.5935 - External negative pressure ventilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External negative pressure ventilator. 868.5935... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5935 External negative pressure ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is...

  6. 21 CFR 868.5935 - External negative pressure ventilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External negative pressure ventilator. 868.5935... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5935 External negative pressure ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is...

  7. 21 CFR 868.5935 - External negative pressure ventilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External negative pressure ventilator. 868.5935... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5935 External negative pressure ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is...

  8. 21 CFR 868.5935 - External negative pressure ventilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false External negative pressure ventilator. 868.5935... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5935 External negative pressure ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is...

  9. Neuroanatomical substrates involved in true and false memories for face.

    PubMed

    Iidaka, Tetsuya; Harada, Tokiko; Kawaguchi, Jun; Sadato, Norihiro

    2012-08-01

    We often mistake an unknown person for a familiar person because of the similarities in facial features. This phenomenon, known as false memory, has been investigated mainly using words, pictures, and shapes. Previous neuroimaging studies on false memory have shown that both true and false memories trigger a similar activation in the medial temporal lobe, suggesting that it plays a common role in both. However, no study to date has investigated neural substrates of false memories for faces. In the present fMRI study, we applied a modified version of the standard false memory paradigm, using morphed pictures of faces, to induce false memory in an MRI environment. We found that activity in the amygdala and orbital cortices was associated with the degree of familiarity of items. In particular, false responses to "lure" items evoked a level of activity in the amygdala between that evoked for correct or incorrect responses to "true" items. This indicates a possible role of the amygdala in false memory. A specific region in the anterior cingulate cortex was involved in false recognition; the activity being correlated to reaction times for the response types. These results suggest that the amygdala is involved in determining the relevance of items; therefore, ambiguousness of lure items in terms of familiarity and novelty may be related to decreased activity in the amygdala. The anterior cingulate activity in false memory may be caused not only by increased effort and motor demand but also by higher mnemonic processing of lure items.

  10. Negative symptoms: psychopathological models.

    PubMed Central

    Ananth, J; Djenderdjian, A; Shamasunder, P; Costa, J; Herrera, J; Sramek, J

    1991-01-01

    The psychopathological manifestations of schizophrenia have been broadly divided into positive and negative symptom groups. Even though there is no definitive consensus, psychomotor agitation, motor excitement, hallucinations, delusions and thought disorder constitute positive and psychomotor retardation, amotivation, apathy and decreased emotional expression are grouped into negative symptoms. The negative symptoms have been reported to appear late in the course of the illness and resistant to treatment with neuroleptics. While these claims have not been substantiated, the current interest on negative symptoms is related to the fact that many nonfunctioning institutionalized as well as ambulatory schizophrenics manifest negative symptoms. As chronic psychiatric beds have become scarce, many patients with negative symptoms who were harbored in the chronic mental hospitals have been released to the community care and some of these patients live on the streets. Thus their visibility has challenged psychiatry to focus its efforts on the etiology and treatment of negative symptoms. PMID:2049366

  11. Script knowledge enhances the development of children's false memories.

    PubMed

    Otgaar, Henry; Candel, Ingrid; Scoboria, Alan; Merckelbach, Harald

    2010-01-01

    We examined whether script knowledge contributes to the development of children's false memories. Sixty 7-year-old and 60 11-year-old children listened to false narratives describing either a high-knowledge event (i.e., fingers being caught in a mousetrap) or a low-knowledge event (i.e., receiving a rectal enema) that were similar in terms of plausibility and pleasantness. Moreover, half of the children in each condition received additional suggestive details about the false events. Across two interviews, children had to report everything they remembered about the events. Script knowledge affected children's false memories in that both younger and older children developed more false memories for the high-knowledge event than for the low-knowledge event. Moreover, at the first interview, additional suggestive details inhibited the development of children's images into false memories.

  12. Ethanol effects on apparent solubility of poorly soluble drugs in simulated intestinal fluid.

    PubMed

    Fagerberg, Jonas H; Al-Tikriti, Yassir; Ragnarsson, Gert; Bergström, Christel A S

    2012-07-02

    Ethanol intake can lead to an unexpected and possibly problematic increase in the bioavailability of druglike compounds. In this work we investigated the effect of ethanol on the apparent solubility and dissolution rate of poorly soluble compounds in simulated intestinal fluid representing a preprandial state. A series of 22 structurally diverse, poorly soluble compounds were measured for apparent solubility and intrinsic dissolution rate (37 °C) in phosphate buffer pH 6.5 (PhB6.5) and fasted state simulated intestinal fluid (FaSSIF, pH 6.5) with and without ethanol at 5% v/v or 20% v/v. The obtained data were used to understand for which molecules ethanol results in an increased apparent solubility and, therefore, may increase the amount of drug absorbed. In FaSSIF20%ethanol 59% of the compounds displayed >3-fold higher apparent solubility than in pure FaSSIF, whereas the effects of 5% ethanol on solubility, in most cases, were negligible. Acidic and neutral compounds were more solubilized by the addition of ethanol than by lecithin/taurocholate aggregates, whereas bases showed a more substance-specific response to the additives in the buffer. The stronger solubilizing capacity of ethanol as compared to the mixed lipid aggregates in FaSSIF was further identified through Spearman rank analyses, which showed a stronger relationship between FaSSIF20%ethanol and PhB6.5,20%ethanol (rS of 0.97) than FaSSIF20%ethanol and FaSSIF (rS of 0.86). No relationships were found between solubility changes in media containing ethanol and single physicochemical properties, but multivariate data analysis showed that inclusion of ethanol significantly reduced the negative effect of compound lipophilicity on solubility. For this data set the higher concentration of ethanol gave a dose number (Do) <1 for 30% of the compounds that showed incomplete dissolution in FaSSIF. Significant differences were shown in the melting point, lipophilicity, and dose profiles between the compounds

  13. The psychological and legal aftermath of false arrest and imprisonment.

    PubMed

    Simon, R I

    1993-01-01

    False arrest and imprisonment can be an extraordinarily stressful psychological trauma. This is clearly demonstrated in the evaluation of forensic cases alleging false arrest and imprisonment, a review of the recent forensic psychiatric literature and reported legal cases. A clinical vignette is presented that illustrates the psychological trauma and sequelae associated with false arrest and imprisonment. Psychiatric treatment of these individuals is discussed. A number of these cases are litigated.

  14. Decay of false vacuum via fuzzy monopole in string theory

    NASA Astrophysics Data System (ADS)

    Kasai, Aya; Ookouchi, Yutaka

    2015-06-01

    We investigate dielectric branes in false vacua in type IIB string theory. The dielectric branes are supported against collapsing by lower energy vacua inside spherical or tubelike branes. We claim that such branes can be seeds for semiclassical (or quantum mechanical) decay of the false vacua, which makes the lifetime of the false vacua shorter. Also, we discuss a topology change of a bubble corresponding to the fuzzy monopole triggered by dissolving fundamental strings.

  15. Non-Gaussianity from false vacuum inflation: old curvaton scenario

    SciTech Connect

    Gong, Jinn-Ouk; Lin, Chunshan; Wang, Yi E-mail: lics@mail.ustc.edu.cn

    2010-03-01

    We calculate the three-point correlation function of the comoving curvature perturbation generated during an inflationary epoch driven by false vacuum energy. We get a novel false vacuum shape bispectrum, which peaks in the equilateral limit. Using this result, we propose a scenario which we call ''old curvaton''. The shape of the resulting bispectrum lies between the local and the false vacuum shapes. In addition we have a large running of the spectral index.

  16. False Paradoxes of Superposition in Electric and Acoustic Waves.

    ERIC Educational Resources Information Center

    Levine, Richard C.

    1980-01-01

    Corrected are several misconceptions concerning the apparently "missing" energy that results when acoustic or electromagnetic waves cancel by destructive interference and the wave impedance reflected to the sources of the wave energy changes so that the input power is reduced. (Author/CS)

  17. Recollection rejection: false-memory editing in children and adults.

    PubMed

    Brainerd, C J; Reyna, V F; Wright, Ron; Mojardin, A H

    2003-10-01

    Mechanisms for editing false events out of memory reports have fundamental implications for theories of false memory and for best practice in applied domains in which false reports must be minimized (e.g., forensic psychological interviews, sworn testimony). A mechanism posited in fuzzy-trace theory, recollection rejection, is considered. A process analysis of false-memory editing is presented, which assumes that false-but-gist-consistent events (e.g., the word SOFA, when the word COUCH was experienced) sometimes cue the retrieval of verbatim traces of the corresponding true events (COUCH), generating mismatches that counteract the high familiarity of false-but-gist-consistent events. Empirical support comes from 2 qualitative phenomena: recollective suppression of semantic false memory and inverted-U relations between retrieval time and semantic false memory. Further support comes from 2 quantitative methodologies: conjoint recognition and receiver operating characteristics. The analysis also predicts a novel false-memory phenomenon (erroneous recollection rejection), in which true events are inappropriately edited out of memory reports.

  18. Identifying apparent velocity changes in cross correlated microseism noise data

    NASA Astrophysics Data System (ADS)

    Friderike Volk, Meike; Bean, Christopher; Lokmer, Ivan; Pérez, Nemesio; Ibáñez, Jesús

    2015-04-01

    Currently there is a strong interest of using cross correlation of ambient noise to retrieve Green's functions. These are usually used to calculate the seismic wave velocity of the subsurface and therefore can be used for subsurface imaging or monitoring of various geological settings where we expect rapid velocity changes (e.g. reservoirs or volcanoes). The assumption of this method is that the wavefields which are correlated must be diffuse. This criterion is fulfilled if the ambient noise sources are uniformly distributed or the scattering in the medium is high enough to mitigate any source directivity. The location of the sources is usually unknown and it can change in time. These temporal and spatial variations of the microseism noise sources may lead to changes in the retrieved Green's functions, and so, to the apparent changes in seismic wave velocities. To further investigate the apparent changes in Green's functions we undertook an active seismic experiment in Tenerife lasting three months. A small airgun was used as an active source and was shooting repeatedly every 15 minutes. The shots and the microseism noise were recorded at several seismic stations at the same time. That data set gives us the opportunity to compare the changes in seismic wave velocity recovered through cross correlation of ambient noise and changes we measure through active shots from the airgun. The aim is to distinguish between apparent seismic velocity changes and seismic velocity changes caused by changes in the medium. We also use the data set to track the direction of the microseism noise sources to see if changes which are only recovered through cross correlation can be related to temporal and spatial variations of the microseism noise sources.

  19. Laryngospasm With Apparent Aspiration During Sedation With Nitrous Oxide.

    PubMed

    Babl, Franz E; Grindlay, Joanne; Barrett, Michael Joseph

    2015-11-01

    Nitrous oxide and oxygen mixture has become increasingly popular for the procedural sedation and analgesia of children in the emergency department. In general, nitrous oxide is regarded as a very safe agent according to large case series. We report a case of single-agent nitrous oxide sedation of a child, complicated by laryngospasm and radiographically confirmed bilateral upper lobe pulmonary opacities. Although rarely reported with parenteral sedative agents, laryngospasm and apparent aspiration has not been previously reported in isolated nitrous oxide sedation. This case highlights that, similar to other sedative agents, nitrous oxide administration also needs to be conducted by staff and in settings in which airway emergencies can be appropriately managed.

  20. Apparent asystole: are we missing a lifesaving opportunity?

    PubMed Central

    Limb, Christopher; Siddiqui, Muhammad A

    2015-01-01

    The use of ultrasonography is rapidly expanding in emergency medicine. Real-time assessment offers clues to prompt diagnosis and creates opportunities for speedy intervention. We present a case of ‘cardiac monitor asystole’ that proved to be ventricular fibrillation on ultrasound examination. Uniquely this case demonstrates that this, typically unrecognised, form of ventricular fibrillation responds to desynchronised defibrillation, with restoration of perfusion for approximately 30 min. With increasing access to ultrasound we believe that further research is indicated to determine whether some cases of apparent asystole may best be treated by defibrillation, presenting an opportunity to save more lives than current protocols achieve. PMID:25777487

  1. Study on Apparent Viscosity and Structure of Foaming Slag

    NASA Astrophysics Data System (ADS)

    Martinsson, Johan; Glaser, Björn; Sichen, Du

    2016-10-01

    Foaming slag was generated using induction heating. The foam was found non-Newtonian having much higher apparent viscosity compared to the dynamic viscosity of pure slag. Quenched foam was examined. The appearance of the foaming slag was very different from silicone oil-gas foam. The size of gas bubbles ranged from 0.1 to 4 mm (while in the case of silicone oil, 1 to 2 mm). The gas fraction in the foam was considerably lower than in the case of silicone oil.

  2. Apparent evaporative resistance at critical conditions for five clothing ensembles.

    PubMed

    Caravello, Victor; McCullough, Elizabeth A; Ashley, Candi D; Bernard, Thomas E

    2008-09-01

    A limiting factor for clothing ensembles inherent during heat stress exposures is the evaporative resistance, which can be used to compare candidate ensembles and in rational models of heat exchange. In this study, the apparent total evaporative resistance of five clothing ensembles (cotton work clothes, cotton coveralls, and coveralls made of Tyvek 1424 and 1427, NexGen and Tychem QC was estimated empirically from wear trials using a progressive heat stress protocol and from clothing insulation adjustments based on ISO 9920 (2007) and wetness. The metabolic rate was moderate at 165 W m(-2) and relative humidity was held at 50%. Twenty-nine heat-acclimated participants (20 men and 9 women) completed trials for all clothing ensembles. A general linear mixed effects model (ensemble and participants as a random effect) was used to analyze the data. Significant differences (p < 0.0001) among ensembles were observed for apparent total evaporative resistance. As expected, Tychem QC had the highest apparent total evaporative resistance at 0.033 kPa m(2) W(-1). NexGen was next at 0.017 kPa m(2) W(-1). These were followed by Tyvek 1424 at 0.015 kPa m(2) W(-1), and Tyvek 1427, Cotton Coveralls and Work Clothes all at 0.013 kPa m(2) W(-1). This wear test method improves on past methods using the progressive protocol to determine evaporative resistance by including the effects of movement, air motion and wetness on the estimate of clothing insulation. The pattern of evaporative resistance is the same as that for critical WBGTs and a linear relationship between apparent total evaporative resistance and WBGT clothing adjustment factor is suggested. With the large sample size, a good estimate of sample variance associated with progressive method can be made, where the standard error is 0.0044 kPa m(2) W(-1) with a 95% confidence interval of 0.0040-0.0050 kPa m(2) W(-1).

  3. Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

    NASA Astrophysics Data System (ADS)

    Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

    2016-04-01

    In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and

  4. An apparently gluten-induced photosensitivity in horses.

    PubMed

    Yeruham, I; Avidar, Y; Perl, S

    1999-12-01

    Primary photosensitization was observed in 3 Appaloosa mares. The skin lesions were diffuse erythema followed by edema and subsequently weeping and finally dry gangrene and ulceration. The severe photosensitivity dermatitis was apparently induced by gluten ingestion. Resolution of lesions occurred after withdrawal of the suspected dairy concentrate feed and prevention of exposure to sunlight. Neither the ponies nor donkey, which were not fed with the suspected concentrate, exhibited similar skin lesions or other clinical abnormalities. Gluten metabolites may contain photodynamic agents that cause photosensitization in horses.

  5. Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

    NASA Technical Reports Server (NTRS)

    Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

    2015-01-01

    A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

  6. Fingerprints of determinism in an apparently stochastic corrosion process.

    PubMed

    Rivera, M; Uruchurtu-Chavarín, J; Parmananda, P

    2003-05-02

    We detect hints of determinism in an apparently stochastic corrosion problem. This experimental system has industrial relevance as it mimics the corrosion processes of pipelines transporting water, hydrocarbons, or other fuels to remote destinations. We subject this autonomous system to external periodic perturbations. Keeping the amplitude of the superimposed perturbations constant and varying the frequency, the system's response is analyzed. It reveals the presence of an optimal forcing frequency for which maximal response is achieved. These results are consistent with those for a deterministic system and indicate a classical resonance between the forcing signal and the autonomous dynamics. Numerical studies using a generic corrosion model are carried out to complement the experimental findings.

  7. Visual Distinctiveness and the Development of Children's False Memories

    ERIC Educational Resources Information Center

    Howe, Mark L.

    2008-01-01

    Distinctiveness effects in children's (5-, 7-, and 11-year-olds) false memory illusions were examined using visual materials. In Experiment 1, developmental trends (increasing false memories with age) were obtained using Deese-Roediger-McDermott lists presented as words and color photographs but not line drawings. In Experiment 2, when items were…

  8. Comparing recollective experience in true and false autobiographical memories.

    PubMed

    Heaps, C M; Nash, M

    2001-07-01

    This study investigated whether true autobiographical memories are qualitatively distinct from false autobiographical memories using a variation of the interview method originally reported by E. F. Loftus and J. Pickrell (1995). Participants recalled events provided by parents on 3 separate occasions and were asked to imagine true and false unremembered events. True memories were rated by both participants and observers as more rich in recollective experience and were rated by participants as more important, more emotionally intense, as having clearer imagery, and as less typical than false memories. Rehearsal frequency was used as a covariate, eliminating these effects. Imagery in true memories was most often viewed from the field perspective, whereas imagery in false memories was most often viewed from the observer perspective. More information was communicated in true memories, and true memories contained more information concerning the consequences of described events. Results suggest repeated remembering can make false memories more rich in recollective experience and more like true memories. Differences between true and false memories suggest some potentially distinct characteristics of false memories and provide insight into the process of false memory creation.

  9. Retrieval Failure Contributes to Gist-Based False Recognition

    ERIC Educational Resources Information Center

    Guerin, Scott A.; Robbins, Clifford A.; Gilmore, Adrian W.; Schacter, Daniel L.

    2012-01-01

    People often falsely recognize items that are similar to previously encountered items. This robust memory error is referred to as "gist-based false recognition". A widely held view is that this error occurs because the details fade rapidly from our memory. Contrary to this view, an initial experiment revealed that, following the same encoding…

  10. 20 CFR 702.217 - Penalty for false statement, misrepresentation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Penalty for false statement, misrepresentation. 702.217 Section 702.217 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION...

  11. 20 CFR 702.217 - Penalty for false statement, misrepresentation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Penalty for false statement, misrepresentation. 702.217 Section 702.217 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION...

  12. 20 CFR 702.217 - Penalty for false statement, misrepresentation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Penalty for false statement, misrepresentation. 702.217 Section 702.217 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION...

  13. 20 CFR 702.217 - Penalty for false statement, misrepresentation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Penalty for false statement, misrepresentation. 702.217 Section 702.217 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION...

  14. 20 CFR 702.217 - Penalty for false statement, misrepresentation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Penalty for false statement, misrepresentation. 702.217 Section 702.217 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION...

  15. The false memory syndrome: Experimental studies and comparison to confabulations

    PubMed Central

    Mendez, M.F.; Fras, I.A.

    2011-01-01

    False memories, or recollections that are factually incorrect but strongly believed, remain a source of confusion for both psychiatrists and neurologists. We propose model for false memories based on recent experimental investigations, particularly when analyzed in comparison to confabulations, which are the equivalent of false memories from neurological disease. Studies using the Deese/Roedinger–McDermott experimental paradigm indicate that false memories are associated with the need for complete and integrated memories, self-relevancy, imagination and wish fulfillment, familiarity, emotional facilitation, suggestibility, and sexual content. In comparison, confabulations are associated with the same factors except for emotional facilitation, suggestibility, and sexual content. Both false memories and confabulations have an abnormal sense of certainty for their recollections, and neuroanatomical findings implicate decreased activity in the ventromedial frontal lobe in this certainty. In summary, recent studies of false memories in comparison to confabulations support a model of false memories as internally-generated but suggestible and emotionally-facilitated fantasies or impulses, rather than repressed memories of real events. Furthermore, like confabulations, in order for false memories to occur there must be an attenuation of the normal, nonconscious, right frontal “doubt tag” regarding their certainty. PMID:21177042

  16. The fSAM Model of False Recall

    ERIC Educational Resources Information Center

    Kimball, Daniel R.; Smith, Troy A.; Kahana, Michael J.

    2007-01-01

    The authors report a new theory of false memory building upon existing associative memory models and implemented in fSAM, the first fully specified quantitative model of false recall. Participants frequently intrude unstudied critical words while recalling lists comprising their strongest semantic associates but infrequently produce other…

  17. False Recognition in Lewy-Body Disease and Frontotemporal Dementia

    ERIC Educational Resources Information Center

    de Boysson, C.; Belleville, S.; Phillips, N. A.; Johns, E. K.; Goupil, D.; Souchay, C.; Bouchard, R.; Chertkow, H.

    2011-01-01

    The primary goal of this study was to evaluate the false recognition phenomenon in persons with frontotemporal dementia (FTD) and those with Lewy-body disease (LBD). Patients with LBD (n=10) or FTD (n=15) and their corresponding controls (n=30) were subjected to the Deese-Roediger-McDermott (DRM) paradigm to induce false recognition. Patients were…

  18. True and False Memories, Parietal Cortex, and Confidence Judgments

    ERIC Educational Resources Information Center

    Urgolites, Zhisen J.; Smith, Christine N.; Squire, Larry R.

    2015-01-01

    Recent studies have asked whether activity in the medial temporal lobe (MTL) and the neocortex can distinguish true memory from false memory. A frequent complication has been that the confidence associated with correct memory judgments (true memory) is typically higher than the confidence associated with incorrect memory judgments (false memory).…

  19. CSI (Crime Scene Induction): Creating False Memories of Committing Crime.

    PubMed

    Porter, Stephen B; Baker, Alysha T

    2015-12-01

    We describe two merging lines of empirical inquiry: entire false memories for autobiographical events and false confessions. A recent study showed that people can be led to remember, and confess to, perpetrating serious crimes that never occurred when confronted with suggestive interview tactics commonly used in police interrogations.

  20. Associations among False Belief Understanding, Counterfactual Reasoning, and Executive Function

    ERIC Educational Resources Information Center

    Guajardo, Nicole R.; Parker, Jessica; Turley-Ames, Kandi

    2009-01-01

    The primary purposes of the present study were to clarify previous work on the association between counterfactual thinking and false belief performance to determine (1) whether these two variables are related and (2) if so, whether executive function skills mediate the relationship. A total of 92 3-, 4-, and 5-year-olds completed false belief,…

  1. 7 CFR 1450.12 - Filing of false claims.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Filing of false claims. 1450.12 Section 1450.12 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  2. 7 CFR 1450.12 - Filing of false claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Filing of false claims. 1450.12 Section 1450.12 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  3. 7 CFR 1450.12 - Filing of false claims.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Filing of false claims. 1450.12 Section 1450.12 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  4. 7 CFR 1450.12 - Filing of false claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Filing of false claims. 1450.12 Section 1450.12 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP)...

  5. 48 CFR 52.214-4 - False Statements in Bids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false False Statements in Bids. 52.214-4 Section 52.214-4 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED) CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses...

  6. Associative false recognition occurs without strategic criterion shifts.

    PubMed

    Gallo, D A; Roediger, H L; McDermott, K B

    2001-09-01

    In the DRM (Deese/Roediger and McDermott) false memory paradigm, subjects studied lists of words associated with nonpresented critical words. They were tested in one of four instructional conditions. In a standard condition, subjects were not warned about the DRM Effect. In three other conditions, they were told to avoid false recognition of critical words. One group was warned before study of the lists (affecting encoding and retrieval processes), and two groups were warned after study (affecting only retrieval processes). Replicating prior work, the warning before study considerably reduced false recognition. The warning after study also reduced false recognition, but only when critical items had never been studied; when critical items were studied in half the lists so that subjects had to monitor memory for their presence or absence, the warning after study had little effect on false recognition. Because warned subjects were trying to avoid false recognition, the high levels of false recognition in the latter condition cannot be due to strategically guessing that critical test items were studied. False memories in the DRM paradigm are not caused by such liberal criterion shifts.

  7. Effects of Aging and Education on False Memory

    ERIC Educational Resources Information Center

    Lee, Yuh-Shiow; Lee, Chia-Lin; Yang, Hua-Te

    2012-01-01

    This study examined the effects of aging and education on participants' false memory for words that were not presented. Three age groups of participants with either a high or low education level were asked to study lists of semantically related words. Both age and education were found to affect veridical and false memory, as indicated in the…

  8. Do Children "DRM" Like Adults? False Memory Production in Children

    ERIC Educational Resources Information Center

    Metzger, Richard L.; Warren, Amye R.; Shelton, Jill T.; Price, Jodi; Reed, Andrea W.; Williams, Danny

    2008-01-01

    The Deese/Roediger-McDermott (DRM) paradigm was used to investigate developmental trends in accurate and false memory production. In Experiment 1, DRM lists adjusted to be more consistent with children's vocabulary were used with 2nd graders, 8th graders, and college students. Accurate and false recall and recognition increased with age, but…

  9. Veridical and False Recall in Adults Who Stutter

    ERIC Educational Resources Information Center

    Byrd, Courtney T.; Sheng, Li; Ratner, Nan Bernstein; Gkalitsiou, Zoi

    2015-01-01

    Purpose: This study used a false memory paradigm to explore the veridical and false recall of adults who stutter. Method: Twelve adults who stutter and 12 age-matched typically fluent peers listened to and then verbally recalled lists of words that consisted of either semantic or phonological associates or an equal number of semantic and…

  10. Recollection Rejection: How Children Edit Their False Memories.

    ERIC Educational Resources Information Center

    Brainerd, C. J.; Reyna, V. F.

    2002-01-01

    Presents new measure of children's use of an editing operation that suppresses false memories by accessing verbatim traces of true events. Application of the methodology showed that false-memory editing increased dramatically between early and middle childhood. Measure reacted appropriately to experimental manipulations. Developmental reductions…

  11. Development of False Memories in Bilingual Children and Adults

    ERIC Educational Resources Information Center

    Howe, Mark L.; Gagnon, Nadine; Thouas, Lisa

    2008-01-01

    The effects of within- versus between-languages (English-French) study and test on rates of bilingual children's and adults' true and false memories were examined. Children aged 6 through 12 and university-aged adults participated in a standard Deese-Roediger-McDermott false memory task using free recall and recognition. Recall results showed…

  12. Estimating the Reliability of Multiple True-False Tests.

    ERIC Educational Resources Information Center

    Frisbie, David A.; Druva, Cynthia A.

    1986-01-01

    This study was designed to examine the level of dependence within multiple true-false test-item clusters by computing sets of item correlations with data from a test composed of both multiple true-false and multiple-choice items. (Author/LMO)

  13. Motives for Filing a False Allegation of Rape.

    PubMed

    De Zutter, André W E A; Horselenberg, Robert; van Koppen, Peter J

    2017-02-17

    The list of motives by Kanin (1994) is the most cited list of motives to file a false allegation of rape. Kanin posited that complainants file a false allegation out of revenge, to produce an alibi or to get sympathy. A new list of motives is proposed in which gain is the predominant factor. In the proposed list, complainants file a false allegation out of material gain, emotional gain, or a disturbed mental state. The list can be subdivided into eight different categories: material gain, alibi, revenge, sympathy, attention, a disturbed mental state, relabeling, or regret. To test the validity of the list, a sample of 57 proven false allegations were studied at and provided by the National Unit of the Dutch National Police (NU). The complete files were studied to ensure correct classification by the NU and to identify the motives of the complainants. The results support the overall validity of the list. Complainants were primarily motivated by emotional gain. Most false allegations were used to cover up other behavior such as adultery or skipping school. Some complainants, however, reported more than one motive. A large proportion, 20% of complainants, said that they did not know why they filed a false allegation. The results confirm the complexity of motivations for filing false allegations and the difficulties associated with archival studies. In conclusion, the list of Kanin is, based on the current results, valid but insufficient to explain all the different motives of complainants to file a false allegation.

  14. 38 CFR 21.9740 - False, late, or missing reports.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false False, late, or missing reports. 21.9740 Section 21.9740 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Pursuit of Courses § 21.9740...

  15. 38 CFR 21.9740 - False, late, or missing reports.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false False, late, or missing reports. 21.9740 Section 21.9740 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Pursuit of Courses § 21.9740...

  16. 38 CFR 21.9740 - False, late, or missing reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false False, late, or missing reports. 21.9740 Section 21.9740 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Pursuit of Courses § 21.9740...

  17. 38 CFR 21.9740 - False, late, or missing reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false False, late, or missing reports. 21.9740 Section 21.9740 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Pursuit of Courses § 21.9740...

  18. 38 CFR 21.9740 - False, late, or missing reports.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false False, late, or missing reports. 21.9740 Section 21.9740 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Pursuit of Courses § 21.9740...

  19. False Belief Understanding in Cantonese-Speaking Children

    ERIC Educational Resources Information Center

    Tardif, Twila; Wellman, Henry M.; Cheung, Kar Man

    2004-01-01

    The present study investigates the performance of 96 Cantonese-speaking three- to five-year-old preschoolers on three false belief tasks--a deceptive object, a change of location, and an unexpected contents task encompassing a variety of task factors. Most importantly, the research examines the possibility that false belief performance depends on…

  20. Negative Ion Density Fronts

    SciTech Connect

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  1. The production of spontaneous false memories across childhood.

    PubMed

    Otgaar, Henry; Howe, Mark L; Peters, Maarten; Smeets, Tom; Moritz, Steffen

    2014-05-01

    We found evidence that the usual developmental trends in children's spontaneous false memories were eliminated using novel stimuli containing obvious themes. That is, children created more false memories than adults when scenes needed to be remembered. In Experiment 1, 7- and 8-year-olds had higher false memory rates than adults when using visual scenes. Experiment 2 showed that gist cuing could not account for this effect. In Experiment 3, children and adults received visual scenes and story contexts in which these scenes were embedded. For both types of stimuli, we found that children had the highest false memory rates. Our results indicate that the underlying theme of these scenes is easily identified, resulting in our developmental false memory trend.

  2. Gain-Scheduled Fault Tolerance Control Under False Identification

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine (Technical Monitor)

    2006-01-01

    An active fault tolerant control (FTC) law is generally sensitive to false identification since the control gain is reconfigured for fault occurrence. In the conventional FTC law design procedure, dynamic variations due to false identification are not considered. In this paper, an FTC synthesis method is developed in order to consider possible variations of closed-loop dynamics under false identification into the control design procedure. An active FTC synthesis problem is formulated into an LMI optimization problem to minimize the upper bound of the induced-L2 norm which can represent the worst-case performance degradation due to false identification. The developed synthesis method is applied for control of the longitudinal motions of FASER (Free-flying Airplane for Subscale Experimental Research). The designed FTC law of the airplane is simulated for pitch angle command tracking under a false identification case.

  3. Effects of forage family on apparent ruminal synthesis of B vitamins in lactating dairy cows.

    PubMed

    Castagnino, D S; Seck, M; Beaudet, V; Kammes, K L; Voelker Linton, J A; Allen, M S; Gervais, R; Chouinard, P Y; Girard, C L

    2016-03-01

    Effects of forage family (legume vs. grass) on apparent ruminal synthesis (ARS) and postruminal supply of B vitamins were evaluated in 2 experiments. Diets containing either alfalfa (AL) or orchardgrass (OG) silages as the sole forage were offered to ruminally and duodenally cannulated lactating Holstein cows in crossover design experiments. Experiment 1 compared diets containing AL and OG [~23% forage neutral detergent fiber (NDF) and ~27% total NDF] offered to 8 cows in two 15-d treatment periods. Experiment 2 compared diets containing AL and OG (~25% forage NDF and ~30% total NDF) offered to 13 cows in two 18-d treatment periods. Thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were analyzed in feeds and duodenal digesta. Apparent ruminal synthesis was calculated as the duodenal flow of each vitamin minus its intake. Forage family affected B vitamin intakes, duodenal flow, and ARS. In both experiments, AL diets increased vitamin B6 and decreased folate intakes. In experiment 1, riboflavin and niacin intakes were greater with the OG diet, whereas in experiment 2 thiamin intake was greater but riboflavin intake was smaller with the OG diet. In spite of the low contribution of either silage to the dietary folate content, folate intake was greater with OG diets than AL due to the difference in soybean meal contribution between diets. Niacin and folate ARS were not affected by the forage family. Duodenal microbial nitrogen flow was positively correlated with ARS of riboflavin, niacin, vitamin B6, folates, and vitamin B12, but tended to be negatively correlated with thiamin ARS. Apparent ruminal synthesis of folates and vitamin B12 appear to be related to microbial biomass activity. Changes in nutrient composition of the diets likely affected the microbial population in the rumen and their B vitamin metabolism.

  4. Apparent quasar disc sizes in the "bird's nest" paradigm

    NASA Astrophysics Data System (ADS)

    Abolmasov, P.

    2017-04-01

    Context. Quasar microlensing effects make it possible to measure the accretion disc sizes around distant supermassive black holes that are still well beyond the spatial resolution of contemporary instrumentation. The sizes measured with this technique appear inconsistent with the standard accretion disc model. Not only are the measured accretion disc sizes larger, but their dependence on wavelength is in most cases completely different from the predictions of the standard model. Aims: We suggest that these discrepancies may arise not from non-standard accretion disc structure or systematic errors, as it was proposed before, but rather from scattering and reprocession of the radiation of the disc. In particular, the matter falling from the gaseous torus and presumably feeding the accretion disc may at certain distances become ionized and produce an extended halo that is free from colour gradients. Methods: A simple analytical model is proposed assuming that a geometrically thick translucent inflow acts as a scattering mirror changing the apparent spatial properties of the disc. This inflow may be also identified with the broad line region or its inner parts. Results: Such a model is able to explain the basic properties of the apparent disc sizes, primarily their large values and their shallow dependence on wavelength. The only condition required is to scatter a significant portion of the luminosity of the disc. This can easily be fulfilled if the scattering inflow has a large geometrical thickness and clumpy structure.

  5. Pore fluid pressure, apparent friction, and Coulomb failure

    USGS Publications Warehouse

    Beeler, N.M.; Simpson, R.W.; Hickman, S.H.; Lockner, D.A.

    2000-01-01

    Many recent studies of stress-triggered seismicity rely on a fault failure model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ′ ≤ 1. These studies may present a misleading view of fault strength and the role of pore fluid pressure in earthquake failure. The parameter μ′ is intended to incorporate the effects of both friction and pore pressure, but is a material constant only if changes in pore fluid pressure induced by changes in stress are proportional to the normal stress change across the potential failure plane. Although specific models of fault zones permit such a relation, neither is it known that fault zones within the Earth behave this way, nor is this behavior expected in all cases. In contrast, for an isotropic homogeneous poroelastic model the pore pressure changes are proportional to changes in mean stress, μ′ is not a material constant, and −∞ ≤ μ′ ≤ +∞. Analysis of the change in Coulomb failure stress for tectonically loaded reverse and strike-slip faults shows considerable differences between these two pore pressure models, suggesting that such models might be distinguished from one another using observations of triggered seismicity (e.g., aftershocks). We conclude that using the constant apparent friction model exclusively in studies of Coulomb failure stress is unwise and could lead to significant errors in estimated stress change and seismic hazard.

  6. Interaction of sleep and emotional content on the production of false memories.

    PubMed

    McKeon, Shannon; Pace-Schott, Edward F; Spencer, Rebecca M C

    2012-01-01

    Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep's effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list's "gist." Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details.

  7. False alarms and incorrect rejections in an information security center: correlation with the frequency of incidents.

    PubMed

    Bruno, Thiers; Abrahão, Julia

    2012-01-01

    This study examines the actions taken by operators aimed at preventing and combating information security incidents at a banking organization. The work utilizes the theoretical framework of ergonomics and cognitive psychology. The method is workplace ergonomic analysis. Its focus is directed towards examining the cognitive dimension of the work environment with special attention to the occurrence of correlations between variability in incident frequency and the results of sign detection actions. It categorizes 45,142 operator decisions according to the theory of signal detection (Sternberg, 2000). It analyzes the correlation between incident proportions (indirectly associated with the cognitive efforts demanded from the operator) and operator decisions. The study demonstrated the existence of a positive correlation between incident proportions and false positive decisions (false alarms). However, this correlation could not be observed in relation to decisions of the false-negative type (incorrect rejection).

  8. Multi-Layer Perceptrons and Support Vector Machines for Detection Problems with Low False Alarm Requirements: an Eight-Month Progress Report

    SciTech Connect

    Chen, B; Hickling, T; Krnjajic, M; Hanley, W; Clark, G; Nitao, J; Knapp, D; Hiller, L; Mugge, M

    2007-01-09

    In this project, the basic problem is to automatically separate test samples into one of two categories: clean or corrupt. This type of classification problem is known as a two-class classification problem or detection problem. In what follows, we refer to clean examples as negative examples and corrupt examples as positive examples. In a detection problem, a classifier decision on any one sample can be grouped into one of four decision categories: true negative, true positive, false negative and false positive. These four categories are illustrated by Table 1. True negatives and true positives are cases where the classifier has made the correct decision. False positives are cases where the classifier decides positive when the true nature of the sample was negative, and false negatives are cases where the classifier decides negative when the sample was actually positive. To evaluate the performance of a classifier, we run the classifier on all the samples of a data set and then count all the instances of true negatives, true positives, false negatives, and false positives. All of the performance metrics in this report are then formed from a combination of these four basic decision categories.

  9. Acute appendicitis due to Cytomegalovirus in an apparently immunocompetent patient: a case report

    PubMed Central

    2014-01-01

    Introduction In healthy subjects, Cytomegalovirus infection can be asymptomatic or manifest as mononucleosis syndrome, but organ disease has also been reported. However, in immunocompromised patients this infection can lead to its most significant and severe disease and even mortality. When Cytomegalovirus causes a gastrointestinal tract infection, it more commonly manifests with luminal tract disease and is usually characterized by ulcerative lesions. Appendicitis is a rare manifestation, and has been reported mainly in human immunodeficiency virus-infected patients or patients with other causes of immunocompromise. Case presentation The authors report on a case of acute primary Cytomegalovirus infection complicated with acute appendicitis due to Cytomegalovirus in an apparently immunocompetent 24-year-old Caucasian man also suffering from primary sclerosing cholangitis and ulcerative colitis. Diagnosis was based on clinical manifestations, serology results, as well as microbiological and histological findings. Treatment consisted of surgery and anti-Cytomegalovirus therapy. Conclusions Cytomegalovirus should be included among the etiologic agents of acute appendicitis in patients with primary sclerosing cholangitis and ulcerative colitis. Currently, there are no definitive data regarding the frequency of Cytomegalovirus appendicitis and the role of anti-Cytomegalovirus treatment in human immunodeficiency virus-negative and apparently immunocompetent subjects. PMID:24612821

  10. Cell surface antigens of human trophoblast: definition of an apparently unique system with a monoclonal antibody.

    PubMed Central

    Mueller, U W; Hawes, C S; Jones, W R

    1986-01-01

    An epitope with apparent specificity for the surface of human syncytiotrophoblast was defined by a murine monoclonal antibody, FDO46B (IgG1, kappa). The epitope was predominantly expressed during the first trimester of pregnancy. Binding was detected on frozen tissue sections and on cultured trophoblast by the immunoperoxidase technique. It was also detected on the surface of a small percentage (less than 10%) of cultured choriocarcinoma cells (JEG-3). A panel of human tissues was negative, as were normal and malignant human lymphocytes. The antigen bearing the FDO46B epitope was still expressed by trophoblast after culture in the presence of tunicamycin, indicating that it is possibly protein in nature. This antigen may have potential utility as a target for a contraceptive vaccine. Images Figure 1 Figure 2 Figure 3 PMID:2428734

  11. Using mass spectrometry to detect hydrolysed gluten in beer that is responsible for false negatives by ELISA.

    PubMed

    Colgrave, Michelle L; Goswami, Hareshwar; Blundell, Malcolm; Howitt, Crispin A; Tanner, Gregory J

    2014-11-28

    Gluten is the collective name for a class of proteins found in wheat, rye, barley and oats. Eating gluten triggers an inappropriate auto-immune reaction in ∼70 million people globally affected by coeliac disease, where the gut reacts to gluten proteins and this triggers an immune response, resulting in intestinal inflammation and damage. Gluten-free foods are now commonplace, however, it is difficult to accurately determine the gluten content of products claiming to be gluten-free using current methodologies as the antibodies are non-specific, show cross-reactivity and have different affinities for the different classes of gluten. The measurement of gluten in processed products is further confounded by modifications to the proteins that occur during processing and in some case hydrolysis of the proteins. In this study, LC-MS/MS was used to profile whole beer, and two beer fractions representing hydrolysed hordeins (<30 kDa) and hordein peptide fragments (<10 kDa). Subsequently, multiple reaction monitoring (MRM) MS enabled the relative quantification of selected peptide fragments in beer and revealed that certain classes of hordein were prone to hydrolysis (B- and D-hordein). Furthermore, select beers contained very high levels of gluten-derived fragments. Strikingly, those beers that contained high levels of B-hordein fragments gave near zero values by ELISA. The hydrolysed fragments that persist in beer show a dose-dependent suppression of ELISA measurement of gluten despite using a hordein standard for calibration of the assay. The development of MS-based methodology for absolute quantification of gluten is required for the accurate assessment of gluten, including hydrolysed forms, in food and beverages to support the industry, legislation and to protect consumers suffering from CD.

  12. Survival analysis for apparent diffusion coefficient measures in children with embryonal brain tumours.

    PubMed

    Grech-Sollars, Matthew; Saunders, Dawn E; Phipps, Kim P; Clayden, Jonathan D; Clark, Chris A

    2012-10-01

    Embryonal brain tumors constitute a large and important subgroup of pediatric brain tumors. Apparent diffusion coefficient (ADC) measures have been previously used in the analysis of these tumors. We investigated a newly described ADC-derived parameter, the apparent transient coefficient in tumor (ATCT), a measure of the gradient change of ADC from the peri-tumoral edema into the tumor core, to study whether ATCT correlates with survival outcome. Sixty-one patients with histologically proven embryonal brain tumors and who had diffusion-weighted imaging (DWI) as part of their clinical imaging were enrolled in a retrospective study correlating ADC measures with survival. Kaplan-Meier survival curves were constructed for extent of surgical resection, age <3 years at diagnosis, tumor type, and metastasis at presentation. A multivariate survival analysis was performed that took into consideration ATCT and variables found to be significant in the Kaplan-Meier analysis as covariates. Results from the multivariate analysis showed that ATCT was the only significant covariate (P < .001). Survival analysis using Kaplan-Meier curves, dividing the patients into 4 groups of increasing values of ATCT, showed that more negative values of ATCT were significantly associated with a poorer prognosis (P < .001). A statistically significant difference was observed for survival data with respect to the change in ADC from edema into the tumor volume. Results show that more negative ATCT values are significantly associated with a poorer survival among children with embryonal brain tumors, irrespective of tumor type, extent of resection, age <3 years at diagnosis, and metastasis at presentation.

  13. Negative Human Interaction

    ERIC Educational Resources Information Center

    Brannan, John M.

    1972-01-01

    This study is an effort to examine man's most negative experiences as he perceives them. The results indicated that teachers were involved more often than any other person in the most negative experience reported. Improved human relations skills are clearly indicated for those in higher education as well as in public schools. (Author)

  14. Semantic representations in the temporal pole predict false memories

    PubMed Central

    Chadwick, Martin J.; Anjum, Raeesa S.; Kumaran, Dharshan; Schacter, Daniel L.; Spiers, Hugo J.; Hassabis, Demis

    2016-01-01

    Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the “semantic hub” of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories. PMID:27551087

  15. Lexical association and false memory for words in two cultures.

    PubMed

    Lee, Yuh-shiow; Chiang, Wen-Chi; Hung, Hsu-Ching

    2008-01-01

    This study examined the relationship between language experience and false memory produced by the DRM paradigm. The word lists used in Stadler, et al. (Memory & Cognition, 27, 494-500, 1999) were first translated into Chinese. False recall and false recognition for critical non-presented targets were then tested on a group of Chinese users. The average co-occurrence rate of the list word and the critical word was calculated based on two large Chinese corpuses. List-level analyses revealed that the correlation between the American and Taiwanese participants was significant only in false recognition. More importantly, the co-occurrence rate was significantly correlated with false recall and recognition of Taiwanese participants, and not of American participants. In addition, the backward association strength based on Nelson et al. (The University of South Florida word association, rhyme and word fragment norms, 1999) was significantly correlated with false recall of American participants and not of Taiwanese participants. Results are discussed in terms of the relationship between language experiences and lexical association in creating false memory for word lists.

  16. [Development of semantic knowledge in children's associative false memory].

    PubMed

    Nabeta, Tomohiro; Mekuta, Jun-ichi; Kamigaki, Akiko; Matsui, Gota; Park, Shin-Young; Yamazaki, Akira

    2008-02-01

    In the Deese-Roediger-McDermott (DRM) procedure, false recall of a word that was not presented (the critical-lure) can be produced when participants study a list of associative words related to the critical-lure. Recently, some studies using the DRM procedure showed that young children did not produce false recall. The present study hypothesized that the children did not produce false recall in those studies because the lists of words did not reflect the children's associative knowledge. To test this possibility, the present study developed lists that reflect the associative knowledge of five-year-old children and examined false recall using the DRM procedure. The results showed that children falsely recalled the critical-lure after studying the lists that reflected the children's associative knowledge, while they did not recall the critical-lure after studying the lists that reflected adults' associative knowledge. The results indicate that children produce false recall when the lists of words reflect those children's associative knowledge. The present finding suggests that the structuring of semantic knowledge that mediates false recall of the critical-lure has developed five years of age.

  17. Collection and evaluation of false alarm signatures in background data

    NASA Astrophysics Data System (ADS)

    Agarwal, Sanjeev; Vulli, Shivakar; Malloy, Neil J.; Lord, Elizabeth M.; Fairley, Josh R.; Sabol, Bruce M.; Johnson, Wesley; Ess, Richard; Trang, Anh H.

    2009-05-01

    A significant amount of background airborne data was collected as part of May 2005 tests for airborne minefield detection at an arid site. The locations of false alarms which occurred consistently during different runs, were identified and geo-referenced by MultiSensor Science LLC. Ground truth information, which included pictures, type qualifiers and some hyperspectral data for these identified false alarm locations, was surveyed by ERDC-WES. This collection of background data, and subsequent survey of the false alarm locations, is unique in that it is likely the first such airborne data collection with ground truthed and documented false alarm locations. A library of signatures for different sources of these false alarms was extracted in the form of image chips and organized into a self-contained database by Missouri S&T. The library contains target chips from airborne mid wave infrared (MWIR) and multispectral imaging (MSI) sensors, representing data for different days, different times of day and different altitudes. Target chips for different surface mines were also added to the database. This database of the target signatures is expected to facilitate evaluation of spectral and shape characteristics of the false alarms, to achieve better false alarm mitigation and improve mine and minefield detection for airborne applications. The aim of this paper is to review and summarize the data collection procedure used, present the currently available database of target chips and make some recommendations regarding future data collections.

  18. Semantic representations in the temporal pole predict false memories.

    PubMed

    Chadwick, Martin J; Anjum, Raeesa S; Kumaran, Dharshan; Schacter, Daniel L; Spiers, Hugo J; Hassabis, Demis

    2016-09-06

    Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the "semantic hub" of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories.

  19. Neural correlates underlying true and false associative memories.

    PubMed

    Dennis, Nancy A; Johnson, Christina E; Peterson, Kristina M

    2014-07-01

    Despite the fact that associative memory studies produce a large number of false memories, neuroimaging analyses utilizing this paradigm typically focus only on neural activity mediating successful retrieval. The current study sought to expand on this prior research by examining the neural basis of both true and false associative memories. Though associative false memories are substantially different than those found in semantic or perceptual false memory paradigms, results suggest that associative false memories are mediated by similar neural mechanisms. Specifically, we found increased frontal activity that likely represents enhanced monitoring and evaluation compared to that needed for true memories and correct rejections. Results also indicated that true, and not false associative memories, are mediated by neural activity in the MTL, specifically the hippocampus. Finally, while activity in early visual cortex distinguished true from false memories, a lack of neural differences between hits and correct rejections failed to support previous findings suggesting that activity in early visual cortex represents sensory reactivation of encoding-related processing.

  20. The relationship between DRM and misinformation false memories.

    PubMed

    Zhu, Bi; Chen, Chuansheng; Loftus, Elizabeth F; Lin, Chongde; Dong, Qi

    2013-08-01

    This research investigated the relationship between false memories induced by two different paradigms (misinformation and Deese-Roediger-McDermott [DRM]). The misinformation effect refers to the phenomenon that a person's recollection of a witnessed event can be altered after exposure to misleading information about the event. DRM false memory represents the intrusion of words that are semantically related but not actually presented in the study session. Subjects (N = 432) completed both misinformation and DRM false memory tests. Results showed a small but significant correlation (r = .12, p = .02) between the misinformation and DRM false memories. Furthermore, using signal detection theory, we found that the discrimination ability index (d') was related to both the misinformation and DRM false memories (r = -.12 and -.13, p = .01), while the response bias was related only to DRM false memory (r = -.46, p < .001). These results suggest that misinformation and DRM false memories generally involve different mechanisms and that their shared mechanism may involve the global discrimination ability.